Merge branch '514146-add-redirect-routes-namespace-id' into 'master'

Add namespace_id column to redirect_routes

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183002



Merged-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Tiger Watson <twatson@gitlab.com>
Reviewed-by: Bogdan Denkovych <bdenkovych@gitlab.com>
Co-authored-by: Shane Maglangit <smaglangit@gitlab.com>