Show an error message and details when authorization fails

When authorization in the popup window fails (e.g. our server's access token request to Canvas fails) the error dialog doesn't contain any information about what went wrong that the user could use to debug or could provide to support:


The server should send the frontend an error message and details that the frontend should show to the user, as other error dialogs elsewhere in the app do. Here's an example from somewhere else in the app: