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/TaskServices/TaskExecutionMode.cs

@@ -13,17 +13,17 @@ namespace Microsoft.SqlTools.ServiceLayer.TaskServices
         /// <summary>
         /// Execute task
         /// </summary>
-        Execute,
+        Execute = 0,
 
         /// <summary>
         /// Script task
         /// </summary>
-        Script,
+        Script = 1,
 
         /// <summary>
         /// Execute and script task
         /// Needed for tasks that will show the script when execution completes
         /// </summary>
-        ExecuteAndScript
+        ExecuteAndScript = 2
     }
 }