Context:
In SUPPORT-7320 a customer had >10k decision definitions and the request to retrieve definitions for the report builder failed hitting the default max bucket limit of elasticsearch.
https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket.html

AT:

• until there is no paging for definition endpoints the by key aggregations should be implemented as composite aggregations and the result collected by scrolling
• a test verifies all definition endpoint that return multiple instances can handle more than 10k definitions