Support Cursor Shape

[bbb651]

I tested listening to CursorNotifyEvents, and for each one requesting GetCursorImageAndName and printing the cursor name (the CursorNotifyEvent::name atom or GetCursorName seem a lot better but I couldn't figure out how to use either of them).
It seems to work pretty well, testing the cursors gtk4-demo, it doesn't seem to work in some sizes and animated cursors seem to only report the cursor name on the first frame and then keep updating the cursor without a name, but for most situations it seems like it can work.
And we can HideCursor/ShowCursor as needed to hide and fallback to client provided cursors. Actually this is not even necessary, we can just ignore the cursor Xwayland sets while we have a cursor shape.

P.S. it would be nice to have a matrix room (or discord) for xwayland-satellite

[bbb651]

I got a PoC working, I'm forcing the cursor shape to crosshair otherwise it's indistinguishable:

I'm destroying the cursor shape device when an unknown cursors which I think is correct? I find the documentation for [wp_cursor_shape_device_v1::destroy](https://wayland.app/protocols/cursor-shape-v1#wp_cursor_shape_device_v1:request:destroy) a bit weird:

Destroy the cursor shape device.

The device cursor shape remains unchanged.

There's also no shape for none so I think that requires calling wl_pointer::set_cursor with null.

[Supreeeme]

What exactly is not working without this?

[bbb651]

This solves cursor mismatch and scaling issue e.g. #83, even ones that are the fault of clients, and it enables things like svg cursors (that support any size and don't take much disk space like Xcursor) for compositors.
I mostly just nerd snipped myself because I found that request in xfixes and it seemed cool to implement, if you think it's too much effort to maintain that's totally reasonable.

[Supreeeme]

Oh, okay. That's fine. I just didn't know what the actual issue was.