Add translation variables for settings in backend and

institution-related pages in frontend

frontend/de/institution.json

@@ -59,6 +59,7 @@
         "lockers": "Schlie\u00dff\u00e4cher",
         "museum_shop": "Museumsshop",
         "babycare_room": "Wickelraum",
-        "ticket_prices": "Eintrittspreise"
+        "ticket_prices": "Eintrittspreise",
+        "online_visitor_statistics": "Besucherstatistik"
     }
 }