Merge branch '389751-show-indicator-in-the-ui-that-code-search-is-served-from-zoekt' into 'master'

Add zoekt search indicator

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/129376



Merged-by: Miguel Rincon <mrincon@gitlab.com>
Approved-by: Serena Fang <sfang@gitlab.com>
Approved-by: Nataliia Radina <nradina@gitlab.com>
Approved-by: Miguel Rincon <mrincon@gitlab.com>
Reviewed-by: Miguel Rincon <mrincon@gitlab.com>
Reviewed-by: Nataliia Radina <nradina@gitlab.com>
Co-authored-by: Tomas Bulva <tbulva@gitlab.com>