Improved login redirect and setup experience

- Updated auth system for mfa to not update intended URL so that the
  user is not redirected to mfa setup after eventual login.
- Added notification for users setting up MFA, after setup when
  redirected back to login screen to advise that MFA setup was complete
  but they need to login again.
- Updated some bits of wording to display better.

app/Http/Middleware/AuthenticatedOrPendingMfa.php

@@ -36,6 +36,6 @@ class AuthenticatedOrPendingMfa
             return $next($request);
         }
 
-        return redirect()->guest(url('/login'));
+        return redirect()->to(url('/login'));
     }
 }