Added record, sequence, union, and map values to represent any protobuf value without requiring type information/.proto files to parse.
Added record, sequence, union, and map values to represent any protobuf value without requiring type information/.proto files to parse.

Added types for above to be used for AT LEAST declaring attributes on operators or subgraphs and likely for parameter values as well.

onnx/onnx,onnx/onnx,onnx/onnx,onnx/onnx