[vulkan] Parameter storage buffer alignment can fail validation

[derek-gerstmann]

As discovered on linux-worker-1 after we updated the Vulkan SDK to v1.3.283 running on an NVIDIA RTX 3070 w/driver 535.161.8.0:

bilateral_grid_process: Structure id 712 decorated as BufferBlock for variable in Uniform storage class must follow relaxed storage buffer layout rules: member 0 contains an array with stride 4 not satisfying alignment to 8

Other apps seem to fail with similar validation failures.

I'm not entirely sure how to handle alignment offsets within the storage buffer used to pass the parameters. We assume they're all packed together, which apparently isn't a valid assumption. So, we'll likely have to pad the buffer, and copy them into offsets that conform to the alignment.