performance issue caused by solves query on chall listing api

https://github.com/CTFd/CTFd/blob/e0290cc67b1af531fd19bfeec3e32ade14e248fd/CTFd/api/v1/challenges.py#L193-L212

why is it necessary to return solves count for all challenges? I didn't see CTFd displaying that info anywhere on the listing page.
nevertheless, it should respect filters in `query_args['q']` and `['field']`, or it would walk through *all* challenges on each request, and stuck the database when there is somewhere around 1k challenges (yes...really).

Start in CTFd/api/v1/challenges.py at lines 193-212 and inspect how the solves count is queried during challenge listing. Reproduce the listing request with a large challenge set, then verify that the query respects query_args['q'] and query_args['field'] and no longer walks through all challenges unnecessarily.

Written by the indexing model from the issue text.