Merge branch 'md-new-crud-services' into 'master'

Add CRUD services for pipeline triggers, use CreateService in endpoints

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/136159



Merged-by: drew stachon <730684-drew@users.noreply.gitlab.com>
Approved-by: drew stachon <730684-drew@users.noreply.gitlab.com>
Reviewed-by: Fabio Pitino <fpitino@gitlab.com>
Reviewed-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>
Co-authored-by: Missy Davies <ms.melissadavies@gmail.com>
Co-authored-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>