Context:
If a collection data source is used by a multi definition report, on deletion the whole report will get removed as a conflicting resource. It would be more intuitive to just remove the particular definition from the report (as well as associated filters) instead.

AT:

• on collection data source deletion definitions are removed from conflicting reports
• filters that refer to the particular definition via `appliedTo` are removed as well
• if the definition is the only definition of a report, the whole report is deleted