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.CoreServices/SqlContext/ISqlToolsSettingsValues.cs

@@ -0,0 +1,33 @@
+//
+// 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.CoreServices.SqlContext
+{
+    /// <summary>
+    /// Defines the common settings used by the tools service
+    /// </summary>
+    public interface ISqlToolsSettingsValues
+    {
+        /// <summary>
+        /// Intellisense specific settings
+        /// </summary>
+        IntelliSenseSettings IntelliSense { get; set; }
+
+        /// <summary>
+        /// Query execution specific settings
+        /// </summary>
+        // QueryExecutionSettings QueryExecutionSettings { get; set; }
+
+        // /// <summary>
+        // /// Formatter settings
+        // /// </summary>
+        // FormatterSettings Format { get; set; }
+
+        /// <summary>
+        /// Object Explorer specific settings
+        /// </summary>
+        ObjectExplorerSettings ObjectExplorer { get; set; }
+    }
+}