Geo admin screen enhancements

What does this MR do?

This MR rewrites Geo admin page (available at /admin/geo_nodes) in Vue to be more manageable.

Why was this MR needed?

Current implementation of Geo nodes admin page is based on plain JavaScript which does DOM manipulation to render and update data, which is not a very efficient approach and makes writing tests for the application much more difficult. Vue works for us!

Screenshots

Desktop Layout

Mobile Layout

Url Insecure Warning

GitLab Version Mismatch

Node Unhealthy

Replication Lag

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
• [ ] If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan

What are the relevant issue numbers?

Closes #4268 (closed), #4179 (closed), #1363 (closed)