Move unused forked code to external directory (#1192)

* Move unused forked code to external directory

* Fix SLN build errors

* Add back resource provider core since it's referenced by main resource provider project

* Update PackageProjects step of pipeline

external/Microsoft.SqlTools.DataProtocol.Contracts/ServerCapabilities/TextDocument.cs

@@ -0,0 +1,76 @@
+//
+// 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.DataProtocol.Contracts.Utilities;
+
+namespace Microsoft.SqlTools.DataProtocol.Contracts.ServerCapabilities
+{
+    public enum TextDocumentSyncKind
+    {
+        None = 0,
+        Full = 1,
+        Incremental = 2
+    }
+
+    /// <summary>
+    /// Defines options for sae notifications
+    /// </summary>
+    public class TextDocumentSaveOptions
+    {
+        /// <summary>
+        /// Whether the client should send the content of the file being saved with the save notification
+        /// </summary>
+        public bool? IncludeText { get; set; }
+    }
+
+    public class TextDocumentSync : Union<TextDocumentSyncOptions, TextDocumentSyncKind?>
+    {
+        public static TextDocumentSync FromTextDocumentSyncKind(TextDocumentSyncKind value)
+        {
+            return new TextDocumentSync
+            {
+                value1 = null,
+                value2 = value
+            };
+        }
+
+        public static TextDocumentSync FromTextDocumentSyncOptions(TextDocumentSyncOptions value)
+        {
+            return new TextDocumentSync
+            {
+                value1 = value,
+                value2 = null
+            };
+        }
+    }
+    
+    public class TextDocumentSyncOptions
+    {
+        /// <summary>
+        /// What kind of change notifications are sent to the server
+        /// </summary>
+        public TextDocumentSyncKind? Change { get; set; }
+        
+        /// <summary>
+        /// Whether open and close notifications are sent to the server
+        /// </summary>
+        public bool? OpenClose { get; set; }
+        
+        /// <summary>
+        /// Options for save notifications
+        /// </summary>
+        public TextDocumentSaveOptions SaveOptions { get; set; }
+    
+        /// <summary>
+        /// Whether notifications indicating the client will save are sent to the server
+        /// </summary>
+        public bool? WillSave { get; set; }
+        
+        /// <summary>
+        /// Whether requests should be sent to the server when the client is about to save
+        /// </summary>
+        public bool? WillSaveWaitUntil { get; set; }
+    }
+}