✨[Feature] Enable conversion of Pytorch tensors <=> Input class in FX frontend

[narendasan]

Is your feature request related to a problem? Please describe.

See #1372 (comment) for more details on what is different

Describe the solution you'd like

We need to get the FX and TS frontends to use the same APIs so it is easier to switch.

Describe alternatives you've considered

Additional context

[peri044]

#1763