allow re-login when authorization fails on editor.edit route
Fixup behavior and styling of editor re-auth.

Closes #2092
- Adds styling for re-auth modal.
- Prevent transition to posts route on success.
- Clear credentials from controller.
- Handle confirmAccept action if form is submitted via 'enter'.
- Only allow re-auth as the user that was previously logged in.
Merge pull request #4602 from jaswilli/better-auth-retry

Allow re-authentication in editor after 401 response