Dark mode in the UI

**Is your feature request related to a problem? Please describe.**
We really need dark mode. Currently it's disabled as the radio button is messed up.

This is a lot of grunt-work... Ideally we could get an AI to do this, but it might require too much human input/decisions.

**Describe the solution you'd like**
Respect system dark mode.

**Additional context**
- Requested by the folks at Scrape Graph
- Current line disabling it: https://github.com/DAGWorks-Inc/burr/blob/aeff00ea545ebd79b96bf4943fee6626e02c4131/telemetry/ui/tailwind.config.js#L18

To test out you'll do the following:
1. check out Burr/fork
2. `pip install -e .`
3. `burr --no-open`
4. (in another terminal) `cd telemetry/ui && npm run start`
5. (if it doesn't open) -- go to http://localhost:3000

Then any changbe to the UI will help.