zink/kopper/apple: MoltenVK, WSI, kopper and xquarts do not work together
This issue is specific to building and running Zink and Kopper on macOS.
The kopper code added to allow Vulkan WSI to be used for display is using XCB WSI structures and functions.
As Mesa is an X11 system for MacOS, this is the correct behaviour and is needed as XQuartz gives X11 handles.
But the only Vulkan implementation on macOS is MoltenVK and its WSI implementation only supports the macOS WSI structures and functions.
This seems to be additionally complicated by the fact that I cannot find any entry points, examples, or reference in XQuarts to obtaining macOS/platform specific handles to be able to pass into the MoltenVK macOS WSI structures and functions.