Extract groups data so we can reuse easier

This is a prerequisite to !483 (merged) so we can reuse the data easier.

I did think about putting this in YAML while I was half way through it..... well, it's been half way through it and it's a bit painful to start over, so I decided to continue.

Putting them into Ruby has greater flexibility anyway.

Here's the dry-run: https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/532054368