chore: import upstream snapshot with attribution

extensions/github-authentication/src/common/errors.ts

@@ -0,0 +1,14 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export const TIMED_OUT_ERROR = 'Timed out';
+
+// These error messages are internal and should not be shown to the user in any way.
+export const USER_CANCELLATION_ERROR = 'User Cancelled';
+export const NETWORK_ERROR = 'network error';
+
+// This is the error message that we throw if the login was cancelled for any reason. Extensions
+// calling `getSession` can handle this error to know that the user cancelled the login.
+export const CANCELLATION_ERROR = 'Cancelled';