Draft: Add some fixes for properly deleting lesson events

aleksis/apps/untis/util/mysql/importers/common_data.py

@@ -448,6 +448,8 @@ def import_supervision_areas(
             if delete:
                 with create_revision():
                     set_comment(_("Deleted by Untis import"))
+                    if supervision.supervision_event:
+                        supervision.supervision_event.delete()
                     supervision.delete()
                 logger.info(f"    Supervision {supervision} deleted")