Add static logger class for azdata extension (#11939)

* Add static logger class for arc extension

* Fix compile errors

* Fix test

extensions/azdata/src/common/logger.ts

@@ -0,0 +1,24 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+
+export class Log {
+	private _output: vscode.OutputChannel;
+
+	constructor() {
+		this._output = vscode.window.createOutputChannel('azdata');
+	}
+
+	log(msg: string): void {
+		this._output.appendLine(msg);
+	}
+
+	show(): void {
+		this._output.show(true);
+	}
+}
+const Logger = new Log();
+export default Logger;