vulkan: support timers on async transfer queues

This requires using host query resets, which requires a new extension.
The extension in question is also promoted to vulkan API version 1.2,
but for some reason, loading the function pointer under the old name
fails, even though the extension text seems to suggest that it should be
available under the new name as well. (But I think this might be a
loader bug). Work around it by just annoyingly introducing the concept
of function aliases.

Side note, the validation layers think this is an error because they're
too old to know about host query resets. I think this commit gives the
term "bleeding edge" a new meaning.