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/Metadata/ObjectMetadata.cs

@@ -0,0 +1,36 @@
+//
+// 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.DataProtocol.Contracts.Metadata
+{
+    /// <summary>
+    /// Metadata type enumeration
+    /// </summary>
+    public enum MetadataType
+    {
+        Table = 0,
+        View = 1,
+        SProc = 2,
+        Function = 3,
+        Schema = 4,
+        Database = 5
+    }
+
+    /// <summary>
+    /// Object metadata information
+    /// </summary>
+    public class ObjectMetadata 
+    {
+        public MetadataType MetadataType { get; set; }
+    
+        public string MetadataTypeName { get; set; }
+
+        public string Schema { get; set; }
+
+        public string Name { get; set; }
+        
+        public string Urn { get; set; }
+    }
+}