RBAC: Fix slow user permission search query on MySQL (#85058)
* Bench testing search user perm
* Add BenchmarkSearchUsersPermissions_1K_1K
* Clarify benchmark searches by action prefix
* Make MySQL more efficient
* Move all filter options
* Expand after assignments union
* update comments
(cherry picked from commit 5e48804364)
Co-authored-by: Gabriel MABILLE <gamab@users.noreply.github.com>