gpui: Add middle and right click mouse events for macOS (#49637)

- [x] Added a solid test coverage and/or screenshots from doing manual
testing
  Manual testing performed successfully on Tahoe 26.2.
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Fixed missing right- and middle-mouse button drag on MacOS

Co-authored-by: MrSubidubi <finn@zed.dev>
3060e4170eGustaf Johansson committed on 3/29/2026, 10:11:57 PM· committed by GitHubparent24ea5e9
1 file changedLine totals unavailable