1. Adding MSAL Authentication provider

2. Removing combined minified graph-js-sdk-core.js
3. Cleaning up Common.ts file
4. Added UT's for Auth provider

Author: muthurathinam-m

core-browserify.js

@@ -0,0 +1,7 @@
+/**
+ * -------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.
+ * See License in the project root for license information.
+ * -------------------------------------------------------------------------------------------
+ */
+export {};