Code improvements (#1649)

* use global namespace for faster lookups
* phpstan level 5

tests/Controller/HomepageControllerTest.php

@@ -36,7 +36,7 @@ class HomepageControllerTest extends ControllerBaseTest
         $client = $this->getClientForAuthenticatedUser(User::ROLE_USER);
 
         $em = $this->getEntityManager();
-        $user = $this->getUserByRole($em, User::ROLE_USER);
+        $user = $this->getUserByRole(User::ROLE_USER);
 
         $pref = (new UserPreference())
             ->setName('login.initial_view')