[export] Use forward hooks to capture module signatures. (#120468)
Summary:
When we export in on strict mode and turn on preserve_module_call_signature, the following assertion error will occur today:
```
child_split[: len(parent_split)] == parent_split
```
This is due to the fact that we're monkey patching forward call directly, which kinda breaks the attribute propagation in the tracer. It's actually better to implement this by using forward hook because we don't have to alter the original module structure at all during export.
Test Plan: CI
Differential Revision: D54102714
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120468
Approved by: https://github.com/ydwu4
