Merge branch '468386-add-custom-role-details-page' into 'master'

Add custom role details page

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/160842



Merged-by: Aaron Huntsman <ahuntsman@gitlab.com>
Approved-by: Ilonah Pelaez <ipelaez@gitlab.com>
Approved-by: Alex Buijs <abuijs@gitlab.com>
Approved-by: Aaron Huntsman <ahuntsman@gitlab.com>
Reviewed-by: Jarka Košanová <jarka@gitlab.com>
Reviewed-by: Alex Buijs <abuijs@gitlab.com>
Reviewed-by: Savas Vedova <svedova@gitlab.com>
Reviewed-by: Artur Fedorov <afedorov@gitlab.com>
Co-authored-by: Daniel Tian <dtian@gitlab.com>