Known Issues:
- When items can horizontal scroll, the right selected border is hidden

TODO:
- [ ] Width calculation is off
- [ ] When scrollbars should autohide they don't until hovering the
panel
- [ ] When switching to and from scrollbar track being visible we are
missing a notify somewhere.

Release Notes:

- Git Panel: Added horizontal scrolling in the git panel

---------

Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Cole Miller <m@cole-miller.net>
Co-authored-by: Cole Miller <cole@zed.dev>