Fix order that InitialContents are applied for Vulkan.

This fixes a bug where the memory backing an image could be initialized
after the image itself, causing corruptions. ApplyInitialContents was
processing the resources in order of resource id. It is possible that a
VkImage and the VkDeviceMemory it is bound to both have InitialContent
(e.g. because the VkDeviceMemory also backs a buffer), and it is also
possible that the VkImage has a lower resource id than the
VkDeviceMemory. In this case, the VkImage's InitialContent is loaded,
and then the VkDeviceMemory's InitialContent is loaded. This direct
write of the backing memory causes the VkImage content to become
undefined and, at least on my AMD card, causes image corruption.

This is fixed by sorting the resource ids by type, which works because
eResDeviceMemory < eResImage. This sorting is applied only for
VulkanResourceManager.