Draft: vulkan/wsi: implement color management protocol
This is using the xx_color_management variant from this MR:
The protocol, among other things, allows the compositor to advertise that it supports displaying images in color spaces other than sRGB. This aligns well with the VK_EXT_swapchain_colorspace extension. The other piece (missing in this MR) would relate to VK_EXT_hdr_metadata.
I have written very little C in my life, and even less driver code, so I'm sure this is a complete mess, stylistically. Sorry about that - I welcome your bikeshedding, nitpicks, etc.