Follow up - Search is slow

Patches related to #40540 (closed) optimized search queries and added limit which made search page quite stable and most of the search requests are processed w/o hitting SQL statement timeout.

https://performance.gitlab.net/dashboard/db/rails-controllers?orgId=1&from=now%2Fd&to=now%2Fd&var-action=SearchController%23show&var-database=Production

There are still some cases though when timeout is hit: https://sentry.gitlap.com/gitlab/gitlabcom/?query=url%3A%22https%3A%2F%2Fgitlab.com%2Fsearch%22+cancel&statsPeriod=14d

• About 10 requests in last 24 hours was cancelled when doing limited issues count query. To mitigate this we may need to either use lower limit (current is 1000), or try to simplify issues count query even more.

• The rest of queries which time out (tens of requests a day) time out when doing project scoped queries - limit is not used, easy fix would be to use limited count for project/group scopes too.