Improve jobs queuing time metric (fixed version)

What does this MR do?

A copy of !17730 (merged) (which was reverted with !18276 (merged)) with an additional fix for #45205 (closed).

Are there points in the code the reviewer needs to double check?

This MR adds again changes, that were already added to master with !17730 (merged), and next reverted with !18276 (merged). I've used the previous branch, and added new commits with fixes on top of them.

Currently the old MR is not reverted on 10-7-stable branch, and is not reverted at all in EE repository. In EE it should be reverted with next automatic ce_to_ee_merge, which should be done tomorrow (today the MR was reverted after it was done already). I'm not sure if it will be automatically propagated to 10-7-stable branches.

When merging and picking this into 10-7-stable branch and EE, we may have a conflicts - I'm ready to help then :)

Why was this MR needed?

For the explanation for initial change, please check !17730 (merged) and #43219 (closed). Additionally this MR contains a fix for #45205 (closed) which was discovered after we've deployed a new version to dev.gitlab.org.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Fixes #45205 (closed)