Add macOS & Wayland events for trackpad zoom and rotate gestures

[pfgithub]

Implements #90 for macOS with two new events: TrackpadZoom and TrackpadRotate. These events can also be implemented for Windows and Linux X11/Wayland, but I do not have a way to test those platforms. Zoom will need to make sure to use a similar scale on all platforms and rotate should use degrees.

• Change log entry in README.md, listing all new symbols
• News page entry, briefly describing the feature
• Guide documentation, with minimal examples, in the relevant guide
• Reference documentation, with all applicable tags
• Cross-references and mentions in appropriate places
• Credits entries for all authors of the feature
• If it adds a new callback, support for it must be added to tests/event.c.

[cblc]

Please, merge this 🙏 🙏 🙏 I really want Magic Trackpad gestures in my apps...

[pfgithub]

I added wayland support, but I'm not really sure where to call _glfwAddPointerGesturesListeners from. The current place works it seems. Also, this needs a rebase to be mergable.

[pfgithub]

This is done. I can't add Windows or X11 support because I can't test them, but if someone wants to here's information:

Windows

Add in src/win32_window in the switch with all the other events like WM_MOUSEWHEEL.

Firefox has an example of using these events: https://searchfox.org/mozilla-central/rev/f2c181a7ab3bfea4d2266521e6eac713630479b3/widget/windows/nsWinGesture.cpp#142-204

You might need to set up gesture config, as described above in that file.

Make sure that the resulting value sent to _glfwInputTrackpadZoom is a scale factor, and _glfwInputTrackpadRotate receives this event's angle minus the previous events angle in degrees centered at 0 (-180 to 180 rather than 0 to 360)

Make sure that zooming doesn't emit ctrl + scroll events once implemented. I'm not sure if it does this currently, but there was a reference to that in the windows documentation.

X11

Example from Gdk: https://gitlab.gnome.org/GNOME/gtk/-/blob/58c49ce6b044c1b08e099cb232f06e71365c5232/gdk/x11/gdkdevicemanager-xi2.c?page=2#L1907-1963