Adding table and model for group namespace filters

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/150092



Merged-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Huzaifa Iftikhar <hiftikhar@gitlab.com>
Reviewed-by: Tiger Watson <twatson@gitlab.com>
Reviewed-by: Huzaifa Iftikhar <hiftikhar@gitlab.com>
Reviewed-by: Abdul Wadood <awadood@gitlab.com>
Co-authored-by: Hitesh Raghuvanshi <hraghuvanshi@gitlab.com>