[[PR Description]]

TODO: 
- [x] Style fold marker
- [x] Editor - Code action icon too large, should use muted color,
should have tooltip
- [ ] Style inline assistant
    - Prompt text gets cut off veritcally
- [x] Line height on inline assist editor isn't tall enough
- Nate: This is my fault due to the line height (relative: 1) we are
setting on non-buffer editors. I'll look into this.
- [ ] Style diagnostic hover (right now it's an opaque box on some
themes)
    - Nate: This needs status tints, we are working on it
- [ ] Hovering over a symbol shows a dialogue that appears underneath
the scroll-bar

Release Notes:

- N/A