Draft: dzn: Use typeless formats for image resources
This way we can avoid the intermediate copy when image formats belong to the same group.
Not sure if doing that defeats some of the optimization d3d12 drivers
might do. If that's the case, we might be able to use a typed-format
when the image doesn't have the TRANSFER_{DST,SRC}
usage or the
CREATE_MUTABLE_FORMAT
flag.
Edited by Boris Brezillon