Adds status popover in runners table header

What does this MR do and why?

Add a status description help popover in the runners list that provides a summary of each of the statuses a runner can have.

MR	status
Update help popover icon (!83735 - merged)	workflowin review
Add a "time in words" formatter for durations (!83740 - merged) (parent MR)	workflowin review
Adds status popover in runners table header (!83305 - merged)	👈 you are here

Screenshots or screen recordings

How to set up and validate locally

0. Logged in as admin, with some runners.
1. Visit the admin runners UI. http://gdk.test:3000/admin/runners
2. Check the help icon, hover on it.

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.

Related to #350184 (closed)