Update server tree action contributions (#15525)

* Update server tree action contributions

* Fix test

src/sql/base/common/codicons.ts

@@ -0,0 +1,17 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/**
+ * Set of IDs used to identify SQL contributed icons, which override the default
+ * codicon behavior vs/base/common/codicons.ts
+ */
+export const enum SqlIconId {
+	book = 'book',
+	dataExplorer = 'dataExplorer',
+	addServerGroupAction = 'add-server-group-action',
+	addServerAction = 'add-server-action',
+	activeConnectionsAction = 'active-connections-action',
+	serverPage = 'server-page'
+}