New Operator, Alert and Proxy request handlers (#1846)

* Add agent dialog class

* Rename agent dialog data classes

* Alert dialog data updates

* Create operator and proxy handlers

extensions/agent/src/interfaces.ts

@@ -0,0 +1,10 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+'use strict';
+
+export interface IAgentDialogData {
+	initialize(): void;
+	save(): void;
+}