Native bindings to the QCOM_texture_foveated_subsampled_layout extension.

This extension builds on QCOM_texture_foveated by introducing a new foveation method bit that aims to reduce memory bandwidth by avoiding the upscaling that occurred as part of the original extension.

With the original FOVEATION_SCALED_BIN_METHOD_BIT_QCOM foveation method, the render target in system memory is entirely populated. The lower resolution framebuffer data is upscaled to fill the entire render target. The subsampled layout method introduced in this extension leaves the framebuffer data at the calculated lower density and instead samples directly from the the lower resolution texels.

The primary usecase this is targeting is traditional VR pipeline. The application eye buffers would be rendered as textures with a subsampled layout and then sampled by the warp process. Sampling from a texture with a subsampled layout requires a new sampler layout qualifier.

Requires QCOM_texture_foveated.