#47 Children and children's children delete when deleting the parent element (state: open)

If tables are linked via the schema kindtabellen and there are corresponding DCA files with childCondition for deletion, this works in the backend - not in the frontend with FEE.

requirement is issue https://github.com/MetaModels/contao-frontend-editing/issues/19

see Workaround https://metamodels.readthedocs.io/de/latest/cookbook/tips/delete-child-items.html