feat: support stylus pressure in macos

[lyonbot]

a PR separated from #276

introduced new pointer events: enter & leave. tested on MacOS. not tested on Linux and Windows, but shall works too

[lyonbot]

conflict resovled

[nulltrope]

Just wanted to say i've been using a build from this branch on mac for a week now with no issues, would be great to get it merged in!

[H-M-H]

Thanks very much for your contribution @lyonbot ! Currently, I do not use macOS, so I can not test this changes, therefore I appreciate your feedback @nulltrope!

One problem I see is that the autopilot library has been patched. @lyonbot instead of patching autopilot, I'd prefer either directly calling the macOS APIs or using another input library that does not require patching. If this is resolved and @nulltrope can verify that everything works, I will probably merge your changes.

[lyonbot]

The patches to autopilot-rs is simple and public here, and the version is locked to commit a92b41ed in Cargo.toml.
The patch also fixes weird behaviors about mouse dragging in MacOS. Because autopilot is tested and it has full features including keyboard, I think patching is still the most quick and low-cost way.

If you still have concerns, you can (1) merge this PR, (2) then bring changes to your own H-M-H/autopilot-rs (3) modify Cargo.toml to use your patched repo. -- which makes no difference IMO.

I've spend too much time on this. the actions to do and a "probably merge" is kinda frustrating to me.

[H-M-H]

No problem @lyonbot :), this is your free time after all. Perhaps I will have a look again when I have some time or someone else feels up to this.