Closes #50624 The empty bottom section of the project panel showed a horizontal scrollbar on hover, but scrolling didn't work there. Added a scroll wheel handler to the blank area that forwards scroll events to the uniform list's scroll handle, making both horizontal and vertical scrolling work from anywhere in the panel. Before you mark this PR as ready for review, make sure that you have: - [x] Added a solid test coverage and/or screenshots from doing manual testing - [x] Done a self-review taking into account security and performance aspects - [x] Aligned any UI changes with the [UI checklist](https://github.com/zedindustries/zed/blob/main/CONTRIBUTING.md#uiux-checklist) Release Notes: - Fixed project panel empty area showing a non-functional scrollbar; scrolling now works from anywhere in the panel --------- Co-authored-by: MrSubidubi <finn@zed.dev>