Agent configuration support classes (WIP) (#632)

* Additional SQL Agent config classes (WIP)

* Fix build breaks

* Clean up job step code

* Add VS Code build files

* Move changes to other machine

* More of the action execution classes

* More execution processing refactors

* More refactoring

* Disable tests for WIP merge

* Fix break on Release config

* Stage changes to other machine.

src/Microsoft.SqlTools.ServiceLayer/Management/Common/ISqlControlCollection.cs

@@ -0,0 +1,24 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+
+namespace Microsoft.SqlTools.ServiceLayer.Management
+{
+	/// <summary>
+	/// defines notion of sitable object
+	/// </summary>
+	public interface IObjectWithSite
+	{
+	    void SetSite(System.IServiceProvider sp);
+    }
+    
+	/// <summary>
+	/// ISqlControlCollection allows access to a collection of dialog views
+	/// </summary>
+	public interface ISqlControlCollection : IObjectWithSite
+	{
+    }
+}