Seating plan integration uses wrong permission names

Example: add_seatingplan_rule is used instead of create_seatingplan_rule

added part::backend type::bug labels

assigned to @hansegucker

created branch 225-seating-plan-integration-uses-wrong-permission-names to address this issue

mentioned in merge request !302 (merged)

closed with merge request !302 (merged)

mentioned in commit 3070497e