Also fixes addressing of MSAA samples 2 and 3 for 64bpp color render targets in the ROV RB implementation on Direct3D 12.
Additionally, with FSI/ROV, alpha test and alpha to coverage are done only if the render target 0 was dynamically written to (according to the Direct3D 9 rules for writing to color render targets, though not sure if they actually apply to the alpha tests on Direct3D 9, but for safety).
There is also some code cleanup for things spotted during the development of the feature.
Transfers are functional on a D3D12-like level, but need additional work so fallbacks are used when multisampled integer sampled images are not supported, and to eliminate transfers between render targets within Vulkan format compatibility classes by using different views directly.
