Traditional renderer operates in sRGB-γ space (as everyone was in 199x).
Making vulkan textures explicitly SRGB for RT renderer breaks color for
trad rendere. Make sure trad renderer still has raw SRGB-unaware texture
sampling.
Adds an UNORM image view for all relevant SRGB textures, and uses them
exclusively for trad renderer. RT still gets proper SRGB views.
Also rename XVK_ to R_Vk for images
Ivan Avdeev