Post #8015: Add comment cache update utility

[mzparacha]

Description

#8015 adds the ability to load comments via pagination instead of directly loading all the comments for a thread. Since with the newer logic we are loading comments in steps and with different cache keys, we need to update a comment in all those caches if a comment gets a mutation action.

This ticket is about creating a utility that can update all comment caches via a simple api.