Add PBandGraphOauth scaffold and auth UI

node_modules/@microsoft/microsoft-graph-client/src/IAuthenticationProvider.ts

@@ -0,0 +1,22 @@
+/**
+ * -------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.
+ * See License in the project root for license information.
+ * -------------------------------------------------------------------------------------------
+ */
+
+import { AuthenticationProviderOptions } from "./IAuthenticationProviderOptions";
+
+/**
+ * @interface
+ * A signature representing Authentication provider
+ * @property {Function} getAccessToken - The function to get the access token from the authentication provider
+ */
+export interface AuthenticationProvider {
+	/**
+	 * To get access token from the authentication provider
+	 * @param {AuthenticationProviderOptions} [authenticationProviderOptions] - The authentication provider options instance
+	 * @returns A promise that resolves to an access token
+	 */
+	getAccessToken: (authenticationProviderOptions?: AuthenticationProviderOptions) => Promise<string>;
+}