Draft: starlight: remove vendoring of universalviewer

Local Checklist

• Read our Contributing guide (for newcomers)
• QA-ed locally?
• Rebased with trunk branch?
• Configuration updated (if needed)?

What does this Merge Request do?

This removes universalviewer from the repo and has docker-compose install it instead.

This also updates universalviewer to 3.0.36. It will conflict with !857 (merged) but that should land first so that if a bug is found, we can roll back to just the update and not the un-vendoring and see if that fixes the issue.

I'm not sure that putting the command in the docker-compose.yml like I did is the right thing to do. My docker know-how is minimal.

Why are we doing this? Any context of related work or Epic?

References !852 (comment 434711188)

Where should a reviewer start?

The docker-compose.yml change and the changes to uv-update which is now uv-setup. The README.md changes are a good place to start too.

Manual testing steps?

Spin it up and make user Universal Viewer still works.