Merge branch '512435-active-context-migration-framework' into 'master'

ActiveContext: Add migration framework

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/178896



Merged-by: Matt Kasa <mkasa@gitlab.com>
Approved-by: Madelein van Niekerk <mvanniekerk@gitlab.com>
Approved-by: Terri Chu <tchu@gitlab.com>
Approved-by: Matt Kasa <mkasa@gitlab.com>
Reviewed-by: Matt Kasa <mkasa@gitlab.com>
Reviewed-by: Dmitry Gruzd <dgruzd@gitlab.com>
Reviewed-by: Terri Chu <tchu@gitlab.com>
Reviewed-by: Madelein van Niekerk <mvanniekerk@gitlab.com>
Co-authored-by: Dmitry Gruzd <dgruzd@gitlab.com>