Feature/serialization exe (#442)

* Initial changes to have serialization generate its own .exe

* Removed additional project from sln file

* remove all references to removed temporary project

* Moved shared contracts into own dll and fixed imports. Addressed PR comments

* Undid having a separate contracts project since that'll be a task for later on. Moved dbcellvalue and saveresultsrequest to Hosting, where they will be imported and shared by the service layer and serialization projects

* Switched backslashes in project reference in csproj file to forward slashes for consistency

* Moved necessary contracts back to service layer. Refactored CommandOptions to reduce code duplication. Addressed miscellaneous PR suggestions

* Accidentally left these files out of previous commit

* Initialized loggers for serialization and credentials with the logging directory provided by the cmd line arg, if there is one

* Changed default log directory paths for serialization and credentials. Removed unnecessary cast and added a copyright

* Changed name of generated executable for serialization service

* removed unnecessary object cast

* removing unnecessary imports and addressing other PR comments

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/Contracts/SaveResultsRequest.cs

@@ -3,7 +3,6 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using System;
 using Microsoft.SqlTools.Hosting.Protocol.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/Contracts/Serialization.cs

@@ -0,0 +1,57 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts
+{
+    /// <summary>
+    /// Class used for storing results and how the results are to be serialized
+    /// </summary>
+    public class SaveResultsInfo
+    {
+        /// <summary>
+        /// String representation of the type that service is supposed to serialize to
+        ///  E.g. "json" or "csv"
+        /// </summary>
+        public string SaveFormat { get; set; }
+
+        /// <summary>
+        /// Path to file that the serialized results will be stored in
+        /// </summary>
+        public string SavePath { get; set; }
+
+        /// <summary>
+        /// Results that are to be serialized into 'SaveFormat' format
+        /// </summary>
+        public DbCellValue[][] Rows { get; set; }
+
+        /// <summary>
+        /// Whether the current set of Rows passed in is the last for this file
+        // </summary>
+        public bool IsLast { get; set; }
+
+        /// <summary>
+        /// Constructor
+        /// </summary>
+        public SaveResultsInfo(string saveFormat, 
+            string savePath, 
+            DbCellValue[][] rows, 
+            bool isLast)
+        {
+            this.SaveFormat = saveFormat;
+            this.SavePath = savePath;
+            this.Rows = Rows;
+            this.IsLast = isLast;
+        }
+    }
+
+    public class SaveAsRequest
+    {
+        public static readonly
+            RequestType<SaveResultsInfo, SaveResultRequestResult> Type =
+            RequestType<SaveResultsInfo, SaveResultRequestResult>.Create("query/saveAs");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/DataStorage/SaveAsExcelFileStreamWriter.cs

@@ -3,11 +3,8 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using System.Text;
 using Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/DataStorage/SaveAsExcelFileStreamWriterHelper.cs

@@ -3,12 +3,12 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts;
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Compression;
 using System.Xml;
+using Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage
 {

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/QueryExecutionService.cs

@@ -4,8 +4,6 @@
 //
 using System;
 using System.Collections.Concurrent;
-using System.Data.Common;
-using System.Data.SqlClient;
 using System.IO;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.ServiceLayer.Connection;