Convert some primitives to HTTP status codes

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/109249



Merged-by: Anna Vovchenko <avovchenko@gitlab.com>
Approved-by: Alex Pennells <apennells@gitlab.com>
Approved-by: Anna Vovchenko <avovchenko@gitlab.com>
Co-authored-by: Coung Ngo <cngo@gitlab.com>