Merge branch '461211-update-imported-from-bb-server' into 'master'

Add `imported_from` value to bb server prs and comments

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/157507



Merged-by: Marc Shaw <mshaw@gitlab.com>
Approved-by: Sam Word <sword@gitlab.com>
Approved-by: Marc Shaw <mshaw@gitlab.com>
Co-authored-by: carlad-gl <cdrago@gitlab.com>