This file changes the non-dispatchable Vulkan handle types. We want to
use some of these handles in utils/VulkanSwapChain.cpp so it needs to
have access to it. The file could include
backend/vulkan/vulkan_platform.h but it seems a bit cleaner to move the
header in common/ instead with a warning if the Vulkan backend isn't
enabled.
This introduce a new FencedDeleter service as part of the Device
objects that tracks when resources are no longer used and deletes them.
BufferVk takes advantage of this to defer the deletion of its handle
that was previously incorrectly delete directly in ~BufferVk.
