Bugfix consume_prefix_in_state_dict_if_present function to keep the order of the state_dict (#117464)
This PR proposes to keep the original order as the original state_dict, as the issue creator proposed. It also removes a bug concerning how ``_metadata`` is handled (see below), as well as other small changes to properly remove the prefix when is present.
In the original code, ``_metadata`` was handled as a ``key``.
```
# also strip the prefix in metadata if any.
if "_metadata" in state_dict:
```
This is not the case, ``_metadata`` is actually an ``attribute``. Hence, the previous condition is changed to:
```
# also strip the prefix in metadata if any.
if hasattr(state_dict, "_metadata"):
```
This PR also includes the necessary test.
Fixes #106942
Co-authored-by: mikaylagawarecki <mikaylagawarecki@gmail.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/117464
Approved by: https://github.com/mikaylagawarecki
