SQL Agent configuration for Operators, Alerts and Proxies (WIP) (#621)

* Initial non-refactored SQL Agent alert classes (WIP)

* Move agent classes into subdirectories

* Refactor the agent config code a bit more

* Add more implementation for handlers

* Add more code to the create alert handler

* Clean up agent alert class

* Clean up alert methods a bit

* Initial Operator contracts

* Additonal SQL Agent config changes

* More Proxy config cleanup

* Cleanup AgentProxy class

* Additional cleanups

* Run SRGen

* Add security service to create credential objects

test/Microsoft.SqlTools.ServiceLayer.IntegrationTests/Agent/AgentTestUtils.cs

@@ -0,0 +1,34 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Threading.Tasks;
+using Microsoft.SqlTools.Hosting.Protocol;
+using Microsoft.SqlTools.ServiceLayer.Agent;
+using Microsoft.SqlTools.ServiceLayer.Agent.Contracts;
+using Moq;
+
+namespace Microsoft.SqlTools.ServiceLayer.IntegrationTests.Agent
+{
+    public static class AgentTestUtils
+    {
+        internal static async Task<AgentAlertInfo[]> GetAgentAlerts(string connectionUri)
+        {
+            var requestParams = new AgentAlertsParams()
+            {
+                OwnerUri = connectionUri
+            };
+
+            var requestContext = new Mock<RequestContext<AgentAlertsResult>>();
+
+            AgentAlertInfo[] agentAlerts = null;
+            requestContext.Setup(x => x.SendResult(It.IsAny<AgentAlertsResult>()))
+                 .Callback<AgentAlertsResult>(r => agentAlerts = r.Alerts);
+
+            AgentService service = new AgentService();
+            await service.HandleAgentAlertsRequest(requestParams, requestContext.Object);
+            return agentAlerts;
+        }
+    }
+}