[API] Expose merged Post information via API

Possibility to retrieve information about merged posts via the API.

This would allow to see which posts have been merged and into which parent post.

Accessing this data is important for managing and analyzing feedback accurately and avoiding duplicated insights when processing data on my end.

Solution

Get Post children that have been merged into it - Search posts by merged into Post ID or Parent Post iD

Get Posts that have been merged or those that are not merged - Filter Posts by has been merged into Post boolean state