Context:
Reports in a collection are only allowed to contain reports that comply with the collections scope.
Therefore we need to extend the process/decision-definition endpoints with the possibility to filter the definitions returned for a specific collection scope.

AT:

• the endpoints `GET /process-definition/definitionVersionsWithTenants` & `GET /decision-definition/definitionVersionsWithTenants` offer a new `filterByCollectionScope` query parameter that expects a collection id and only returns definitions in the scope of that collection
• ideally the collection scope is used as a filter criteria on obtaining the relevant definitions
• the API changes are documented