Fakify leaf of FunctionalTensor (#107062)
This PR allows dynamo to fakify FunctionalTensorWrapper by unwrapping, replacing and wrapping again for FunctionalTensorWrapper so that FunctionalTensorWrapper can be passed in as input for dynamo.optimize and we can support something like this
```python
ff = torch.func.functionalize(f)
torch.compile(ff)(x)
```
This PR didn't follow the \_\_tensor_flatten\_\_ and \_\_tensor_unflatten\_\_ protocol right now because we're not sure the plan of doing that for FunctionalTensorWrapper (it's implemented in C++).
**Test Plan:**
Add a new test.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107062
Approved by: https://github.com/zou3519
ghstack dependencies: #107042
