feat: Ensure correct groups are creeated with permissions

src/fellchensammlung/apps.py

@@ -1,6 +1,10 @@
 from django.apps import AppConfig
-
+from .tools.signals import ensure_groups
+from django.db.models.signals import post_migrate
 
 class FellchensammlungConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'fellchensammlung'
+
+    def ready(self):
+        post_migrate.connect(ensure_groups, sender=self)