Similarly to PixelFormat. Will be useful for Vulkan, unfortunately not
so much for GL because there the format is specified by three orthogonal
values and it's a terrible mess.
With API analogous to the (relatively) new AnimationData -- with one
buffer containing all index data and one buffer containing all vertex
data, both meant to be uploaded as-is to the GPU.
This will eventually replace MeshData2D and MeshData3D, backwards
compatibility and wiring up to other APIs will be done in follow-up
commits.
This deliberately doesn't follow the PixelFormat enum naming, as RGBA
components make no sense for most vertex data. Checking Metal and
WebGPU, they seem to have arrived at a similar conclusion, only VkFormat
is an outlier.