Convert DX12 Binary Blobs in Functions

[andrew-lunarg]

Provide a mechanism for registering function and method arguments to be dumped to separate binary files with a single line in the Python generator of the DX12 JSON Consumer.

Example usage provided for one argument:

ID3D12Device.CreateRootSignature(...,pBlobWithRootSignature)

Follow-up to PR https://github.com/LunarG/gfxreconstruct/pull/1362