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

src/Microsoft.SqlTools.ServiceLayer/Security/Credential.cs

@@ -0,0 +1,114 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections;
+using System.ComponentModel;
+using System.Data;
+using System.Data.SqlClient;
+using System.Xml;
+using Microsoft.SqlServer.Management.Common;
+using Microsoft.SqlServer.Management.Sdk.Sfc;
+using Microsoft.SqlServer.Management.Smo;
+using Microsoft.SqlServer.Management.Diagnostics;
+using Microsoft.SqlTools.ServiceLayer.Management;
+using Microsoft.SqlTools.ServiceLayer.Admin;
+
+namespace  Microsoft.SqlTools.ServiceLayer.Security
+{
+    internal class Credential : ManagementActionBase
+    {
+
+// #region Trace support
+//         private const string componentName = "Credential";
+
+//         public string ComponentName
+//         {
+//             get
+//             {
+//                 return componentName;
+//             }
+//         }
+// #endregion
+
+#region Constants
+        private const int MAX_SQL_SYS_NAME_LENGTH = 128; // max sql sys name length
+        private const string PASSWORD_MASK_STRING = "**********";
+#endregion
+
+#region Variables
+        private CredentialData credentialData = null;
+#endregion
+
+#region Constructors / Dispose
+        /// <summary>
+        /// required when loading from Object Explorer context
+        /// </summary>
+        /// <param name="context"></param>
+        public Credential(CDataContainer context)
+        {
+            this.DataContainer = context;
+            this.credentialData = new CredentialData(context);
+            this.credentialData.Initialize();
+        }
+
+        /// <summary> 
+        /// Clean up any resources being used.
+        /// </summary>
+        protected override void Dispose( bool disposing )
+        {
+            base.Dispose( disposing );
+            if (disposing == true)
+            {
+                if (this.credentialData != null)
+                {
+                    this.credentialData.Dispose();
+                }
+            }
+        }
+#endregion
+
+#region Overrides SqlManagementUserControl
+        /// <summary>
+        /// called on background thread by the framework to execute the action
+        /// </summary>
+        /// <param name="node"></param>
+        public void OnRunNow(object sender)
+        {
+            this.credentialData.SendDataToServer();
+
+        }
+
+#endregion
+
+        /// <summary>
+        /// update logic layer based on content of user interface
+        /// </summary>
+        private void UpdateLogicLayer()
+        {
+    
+            this.credentialData.CredentialName = "this.textBoxCredentialName.Text";
+            this.credentialData.CredentialIdentity = "this.textBoxIdentity.Text";
+
+
+            this.credentialData.SecurePassword = AdminService.BuildSecureStringFromPassword("password");
+            this.credentialData.SecurePasswordConfirm = AdminService.BuildSecureStringFromPassword("password");
+
+            if (this.ServerConnection.ServerVersion.Major >= 10)
+            {
+                // need to update only during create time
+                this.credentialData.IsEncryptionByProvider = true; //this.checkBoxUseProvider.Checked;
+                if (this.credentialData.IsEncryptionByProvider)
+                {
+                    this.credentialData.ProviderName = "this.comboBoxProviderName.SelectedItem.ToString()";
+                }
+                else
+                {
+                    this.credentialData.ProviderName = string.Empty;
+                }
+            }
+        }
+    }
+}