Feature: occlusion queries

[Admer456]

NVRHI has timer queries and event queries. However, I think it would be useful to have occlusion queries too, like in NRI.

Without them, I'd have to use a workaround such as rendering into a low-res framebuffer and using a compute shader to count pixels, which I guess would be significantly slower than the real thing, but I've never tried. Directly using the rendering API is not preferable.

What are your thoughts on this?