ONNX Transform changes output types

[rogancarr]

Serializing and deserializing a model to and from ONNX not only changes the names of the output (#2980) but also changes the types of the output. For example, a Score column produced by a model (R4/float) becomes a Vec<R4, 1, 1>.

[singlis]

See #2980, this is also by design as ONNX does deal with vector types and will create a float[1] for a ML.Net floating point output.

[rogancarr]

Thanks for investigating @singlis ! I'll close the issue now. We can just add a comments to the text and samples so that people will know what to expect.