wayland: implement wl_fixes
Implements the wl_fixes
interface introduced in https://gitlab.freedesktop.org/wayland/wayland/-/merge_requests/388. Closes #253 (closed).
Requires libwayland 1.24 (currently, 1.23.90) to have an effect, it changes nothing if compiling for older versions. (CI has 1.23.x so it's not building the new code.)
I think this is correct (I based it off the wlroots implementation), but I don't really know what I'm doing. I tested it with the Mesa MR, which successfully invokes the protocol when running Vulkan apps.