Automatically Logout Banned Users (#12037)

* wip

* logout banned users, fix and refactor language library and middleware

* req.locals -> res.locals

* fix tests

* redirect to login page

website/server/controllers/top-level/auth.js

@@ -28,7 +28,9 @@ api.logout = {
   async handler (req, res) {
     if (req.logout) req.logout(); // passportjs method
     req.session = null;
-    res.redirect('/');
+
+    const redirectUrl = req.query.redirectToLogin === 'true' ? '/login' : '/';
+    res.redirect(redirectUrl);
   },
 };