Add a script to analyze Application Settings

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/166509



Merged-by: David Dieulivol <ddieulivol@gitlab.com>
Approved-by: Thong Kuah <tkuah@gitlab.com>
Approved-by: David Dieulivol <ddieulivol@gitlab.com>
Reviewed-by: Rémy Coutable <remy@rymai.me>
Reviewed-by: Thong Kuah <tkuah@gitlab.com>
Reviewed-by: Krasimir Angelov <kangelov@gitlab.com>
Co-authored-by: Rémy Coutable <remy@rymai.me>