Add basic runner details in admin view runner

What does this MR do and why?

This change adds basic details for the read-only admin page for runners as a first MCV of the page.

This page is behind a feature flag, so no changelog is included

👋 This MR is a big large, but I think it has a well defined scope, so I have decided to ask for reviews.

Iteration Question

Would we feel conformable releasing this early version of the page to more users? What would we be missing to deliver this (e.g. enable feature flag)?

Screenshots or screen recordings

Full figma design for reference

How to set up and validate locally

0. With at least one runner created.
1. Enable feature flag: in your prompt, type rails c and then Feature.enable(:runner_read_only_admin_view)
2. Go to Admin -> Runners
3. Click on the link (id and token) of a runner
4. Verify page contains correct data
   • Click on the edit page and breadcrumbs to confirm links work correctly.

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 #347856 (closed)