Merge branch '442204_jmontal_add_restricted_frontend' into 'master'

Add frontend for user registration restrictions

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/148905



Merged-by: Robert Hunt <rhunt@gitlab.com>
Approved-by: Russell Dickenson <rdickenson@gitlab.com>
Approved-by: Rudy Crespo <rcrespo@gitlab.com>
Approved-by: David Dieulivol <ddieulivol@gitlab.com>
Approved-by: Heinrich Lee Yu <heinrich@gitlab.com>
Approved-by: Robert Hunt <rhunt@gitlab.com>
Approved-by: Drew Blessing <drew@gitlab.com>
Reviewed-by: Robert Hunt <rhunt@gitlab.com>
Reviewed-by: Jay Montal <jmontal@gitlab.com>
Reviewed-by: Rudy Crespo <rcrespo@gitlab.com>
Co-authored-by: Jay Montal <jmontal@gitlab.com>