Show which CI job currently uses the resource group

What does this MR do and why?

This MR implements Show which CI job currently uses the resource g... (#383710 - closed), which significantly improves the investigation in #381139 (closed).

Screenshots or screen recordings

Peek_2023-03-29_14-31

How to set up and validate locally

1. Create a .gitlab-ci.yml with the following content:

deploy:
    script: echo
    resource_group: prd

1. Run a couple of pipelines.
2. Visit a job that is waiting for resource.
3. Click "See the job that is currently using the resource" button.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.