Use staging buffers for vertex attributes and indices in [HPP]GLTFLoader about vulkan-samples HOT 2 OPEN

The version of the VMA in use is fairly out of date. It appears to be a development version of 3.0.0, but from 2020, while 3.0.0 itself wasn't released until 2022, and 3.0.1 shortly after that.

I'm working on a PR that will update to the 3.0.1 release tag, and will default all parameters of type VmaMemoryUsage to VMA_MEMORY_USAGE_AUTO. This should cause the VMA to automatically infer what kind of memory it should allocate from a combination of the buffer/image usage flags and the VmaAllocationCreateFlags. Staging buffers created should be created with VMA_ALLOCATION_CREATE_MAPPED_BIT | VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT and if the destination buffer is created with VMA_MEMORY_USAGE_AUTO and doesn't include a mapping bit it should automatically get memory from a device-only pool.

from vulkan-samples.

Actually, I suspect part of the problem is that both HPPBuffer and Buffer automatically default to VMA_ALLOCATION_CREATE_MAPPED_BIT, which typically forces host memory.

Unfortunately this means this PR will be more complicated than I thought, because I can't make it a drop in replacement if that parameters is changing from VMA_ALLOCATION_CREATE_MAPPED_BIT to 0.

from vulkan-samples.