Shape inference for user-defined functions in TF. For now it is completely...

Shape inference for user-defined functions in TF. For now it is completely "opt-in" via ShapeRefiner API and it doesn't yet affect any existing validation and inferences anywhere. Eventually graph validation should start using it.

Doesn't yet support recursive functions and doesn't yet support more complex shape propagation scenarios where several iterations may be needed to infer shapes.

PiperOrigin-RevId: 170078811