Make DataParallel generic (#102455)
Fixes #102441
improves type hinting of the module attribute, since it can easily be bound in `DataParallel.__init__`
```python
from torch.nn import DataParallel
class MyModule(Module):
...
my_data_parallel = DataParallel(MyModule(), device_ids=[0, 1, 2])
reveal_type(my_data_parallel) # Type of "my_data_parallel" is "DataParallel[MyModule]"
reveal_type(my_data_parallel.module) # Type of "my_data_parallel.module" is "MyModule"
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/102455
Approved by: https://github.com/Skylion007
