fix: #7038, autoLocale logic not playing nicely with no-refresh auths (#7059)

* fix: #7038, autoLocale logic not playing nicely with no-refresh auths

- on login, req.query.lang is deleted (since it seems to be left over)
- on logout, the middleware.autoLocale is executed, which resets
  req.query.lang
- middleware.autoLocale is new, just refactored existing logic in
  webserver.js into new middleware method.

* style: tests, use lodash

* fix: timeago strings not switching languages on login or out

src/controllers/authentication.js

@@ -284,6 +284,8 @@ function continueLogin(req, res, next) {
 				});
 			});
 		} else {
+			delete req.query.lang;
+
 			async.parallel({
 				doLogin: async.apply(authenticationController.doLogin, req, userData.uid),
 				header: async.apply(middleware.generateHeader, req, res, {}),