Add scripting API implemented by the SqlScriptPublishModel (#316)

Update the ScriptingService to expose new scripting JSON-RPC APIs that use the SqlScriptPublishModel for script generation.

The SqlScriptPublishModel is the model behind the SSMS scripting wizard. To enable scripting for CLI tools, we've ported SqlScriptPublishModel to .NET Core. The SqlScriptPublishModel wraps the SMO scripting APIs for .sql script generation.

1) Added three new requests to the ScriptingService: ScriptingRequest, ScriptingListObjectsRequest, ScriptingCancelRequest.
2) Generating scripts are long running operations, so the ScriptingRequest and ScriptingListObjectsRequest kick off a long running scripting task and return immediately.
3) Long running scripting task reports progress and completion, and can be cancelled by a ScriptingCancelRequest request.
4) Bumped the SMO nuget package to 140.17049.0. This new version contains a signed SSMS_Rel build of SMO with the SqlScriptPublishModel.
5) For testing, adding the Northwind database schema

TODO (in later pull requests)
1) Integrate the new ScriptingService APIs with the ConnectionService
2) Integrate with the metadata support recently added

src/Microsoft.SqlTools.ServiceLayer/Scripting/Contracts/ScriptingOptions.cs

@@ -0,0 +1,258 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+namespace Microsoft.SqlTools.ServiceLayer.Scripting.Contracts
+{
+    /// <summary>
+    /// Defines the scripting options.
+    /// </summary>
+    public class ScriptOptions
+    {
+        /// <summary>
+        /// Generate ANSI padding statements
+        /// </summary>
+        public bool? ScriptAnsiPadding { get; set; } = false;
+
+        /// <summary>
+        /// Append the generated script to a file
+        /// </summary>
+        public bool? AppendToFile { get; set; } = false;
+
+        /// <summary>
+        /// Continue to script if an error occurs. Otherwise, stop.
+        /// </summary>
+        /// <remarks>
+        /// The default is true.
+        /// </remarks>
+        public bool? ContinueScriptingOnError { get; set; } = true;
+
+        /// <summary>
+        /// Convert user-defined data types to base types.
+        /// </summary>
+        public bool? ConvertUDDTToBaseType { get; set; } = false;
+
+        /// <summary>
+        /// Generate script for dependent objects for each object scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default is false.
+        /// </remarks>
+        public bool? GenerateScriptForDependentObjects { get; set; } = false;
+
+        /// <summary>
+        /// Include descriptive headers for each object generated.
+        /// </summary>
+        /// <remarks>
+        /// The default is true.
+        /// </remarks>
+        public bool? IncludeDescriptiveHeaders { get; set; } = true;
+
+        /// <summary>
+        /// Check that an object with the given name exists before dropping or altering or that an object with the given name does not exist before creating.
+        /// </summary>
+        public bool? IncludeIfNotExists { get; set; } = false;
+
+        /// <summary>
+        /// Script options to set vardecimal storage format.
+        /// </summary>
+        public bool? IncludeVarDecimal { get; set; } = true;
+
+        /// <summary>
+        /// Include system generated constraint names to enforce declarative referential integrity.
+        /// </summary>
+        public bool? ScriptDriIncludeSystemNames { get; set; } = false;
+
+        /// <summary>
+        /// Include statements in the script that are not supported on the specified SQL Server database engine type.
+        /// </summary>
+        public bool? IncludeUnsupportedStatements { get; set; } = true;
+
+        /// <summary>
+        /// Prefix object names with the object schema.
+        /// </summary>
+        /// <remarks>
+        /// The default is true.
+        /// </remarks>
+        public bool? SchemaQualify { get; set; } = true;
+
+        /// <summary>
+        /// Script options to set bindings option.
+        /// </summary>
+        public bool? Bindings { get; set; } = false;
+
+        /// <summary>
+        /// Script the objects that use collation.
+        /// </summary>
+        public bool? Collation { get; set; } = false;
+
+        /// <summary>
+        /// Script the default values.
+        /// </summary>
+        /// <remarks>
+        /// The default is true.
+        /// </remarks>
+        public bool? Default { get; set; } = true;
+
+        /// <summary>
+        /// Script Object CREATE/DROP statements.  
+        /// Possible values: 
+        ///   ScriptCreate
+        ///   ScriptDrop
+        ///   ScriptCreateDrop
+        /// </summary>
+        /// <remarks>
+        /// The default is ScriptCreate.
+        /// </remarks>
+        public string ScriptCreateDrop { get; set; } = "ScriptCreate";
+
+        /// <summary>
+        /// Script the Extended Properties for each object scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default is true.
+        /// </remarks>
+        public bool? ScriptExtendedProperties { get; set; } = true;
+
+        /// <summary>
+        /// Script only features compatible with the specified version of SQL Server.  Possible values:
+        ///   Script90Compat
+        ///   Script100Compat
+        ///   Script105Compat
+        ///   Script110Compat
+        ///   Script120Compat
+        ///   Script130Compat
+        ///   Script140Compat  
+        /// </summary>
+        /// <remarks>
+        /// The default is Script140Compat.
+        /// </remarks>
+        public string ScriptCompatibilityOption { get; set; } = "Script140Compat";
+
+        /// <summary>
+        /// Script only features compatible with the specified SQL Server database engine edition.
+        /// Possible Values:
+        ///   SqlServerPersonalEdition
+        ///   SqlServerStandardEdition 
+        ///   SqlServerEnterpriseEdition 
+        ///   SqlServerExpressEdition
+        ///   SqlAzureDatabaseEdition
+        ///   SqlDatawarehouseEdition
+        ///   SqlServerStretchEdition 
+        /// </summary>
+        public string TargetDatabaseEngineEdition { get; set; } = "SqlServerEnterpriseEdition";
+
+        /// <summary>
+        /// Script only features compatible with the specified SQL Server database engine type.
+        /// Possible Values:
+        ///   SingleInstance
+        ///   SqlAzure
+        /// </summary>
+        public string TargetDatabaseEngineType { get; set; } = "SingleInstance";
+
+        /// <summary>
+        /// Script all logins available on the server. Passwords will not be scripted.
+        /// </summary>
+        public bool? ScriptLogins { get; set; } = false;
+
+        /// <summary>
+        /// Generate object-level permissions.
+        /// </summary>
+        public bool? ScriptObjectLevelPermissions { get; set; } = false;
+
+        /// <summary>
+        /// Script owner for the objects.
+        /// </summary>
+        public bool? ScriptOwner { get; set; } = false;
+
+        /// <summary>
+        /// Script statistics, and optionally include histograms, for each selected table or view.
+        /// Possible values:
+        ///   ScriptStatsNone
+        ///   ScriptStatsDDL
+        ///   ScriptStatsAll
+        /// </summary>
+        /// <remarks>
+        /// The default value is ScriptStatsNone.
+        /// </remarks>
+        public string ScriptStatistics { get; set; } = "ScriptStatsNone";
+
+        /// <summary>
+        /// Generate USE DATABASE statement.
+        /// </summary>
+        public bool? ScriptUseDatabase { get; set; } = true;
+
+        /// <summary>
+        /// Generate script that contains schema only or schema and data.
+        /// Possible Values:
+        ///   SchemaAndData
+        ///   DataOnly
+        ///   SchemaOnly
+        /// </summary>
+        /// <remarks>
+        /// The default value is SchemaOnly.
+        /// </remarks>
+        public string TypeOfDataToScript { get; set; } = "SchemaOnly";
+
+        /// <summary>
+        /// Scripts the change tracking information.
+        /// </summary>
+        public bool? ScriptChangeTracking { get; set; } = false;
+
+        /// <summary>
+        /// Script the check constraints for each table or view scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default value is true.
+        /// </remarks>
+        public bool? ScriptCheckConstraints { get; set; } = true;
+
+        /// <summary>
+        /// Scripts the data compression information.
+        /// </summary>
+        public bool? ScriptDataCompressionOptions { get; set; } = false;
+
+        /// <summary>
+        /// Script the foreign keys for each table scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default value is true.
+        /// </remarks>
+        public bool? ScriptForeignKeys { get; set; } = true;
+
+        /// <summary>
+        /// Script the full-text indexes for each table or indexed view scripted.
+        /// </summary>
+        public bool? ScriptFullTextIndexes { get; set; } = false;
+
+        /// <summary>
+        /// Script the indexes (including XML and clustered indexes) for each table or indexed view scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default value is true.
+        /// </remarks>
+        public bool? ScriptIndexes { get; set; } = true;
+
+        /// <summary>
+        /// Script the primary keys for each table or view scripted
+        /// </summary>
+        /// <remarks>
+        /// The default value is true.
+        /// </remarks>
+        public bool? ScriptPrimaryKeys { get; set; } = true;
+
+        /// <summary>
+        /// Script the triggers for each table or view scripted
+        /// </summary>
+        public bool? ScriptTriggers { get; set; } = false;
+
+        /// <summary>
+        /// Script the unique keys for each table or view scripted.
+        /// </summary>
+        /// <remarks>
+        /// The default value is true.
+        /// </remarks>
+        public bool? UniqueKeys { get; set; } = true;
+    }
+}