reporting cleanup (#1903)

- show form error when trying to load invalid user
- added non-breaking space to first table cells to allow copy&paste to excel
- added several css classes to allow customizations
- remove team assignment check for user selection

src/Controller/ReportingController.php

@@ -65,17 +65,7 @@ final class ReportingController extends AbstractController
             return false;
         }
 
-        $currentUser = $this->getUser();
-
-        if ($currentUser->canSeeAllData()) {
-            return true;
-        }
-
-        if ($currentUser->hasTeamAssignment()) {
-            return true;
-        }
-
-        return false;
+        return true;
     }
 
     /**