Add missing type hints for all flavors of RoBERTa PyTorch models.
# What does this PR do?

I added type hints for all `RoBERTa` PyTorch classes as described in #16059 .
As I commented on the linked issue, `CamemBERT` inherits from `RoBERTa`, so it should be also good for PyTorch version of `CamemBERT` models.

@Rocketknight1 

I was not sure about `encoder_hidden_states` and `encoder_attention_mask` which have `torch.FloatTensor` as type in the docstring, but I don't know if it needs to be specified or `torch.Tensor` is enough. Tell me if I need to change that.


**EDIT:** Oh it seems that I have put some `torch.LongTensor` like `inputs_ids` as `torch.Tensor`.
_The documentation is not available anymore as the PR was closed or merged._<|||||>@ChainYo it's totally okay to just use `torch.Tensor`, specifying `torch.FloatTensor` or `torch.LongTensor` is a bonus but not at all necessary!

Also, this PR looks great, but note that the methods can return a tuple if `return_dict` is False, so the real return type is usually `Union[Tuple, OutputClass]` and not just `OutputClass`!<|||||>> @ChainYo it's totally okay to just use `torch.Tensor`, specifying `torch.FloatTensor` or `torch.LongTensor` is a bonus but not at all necessary!
> 
> Also, this PR looks great, but note that the methods can return a tuple if `return_dict` is False, so the real return type is usually `Union[Tuple, OutputClass]` and not just `OutputClass`!

Fine, I will change that.