Token type ids generation func. for Bert-like models
# What does this PR do?

For a text sequence input (separated with comma), Bert tokenizer nicely create an input_ids with [SEP] token inside and proper token_type_ids as well. However for input_ids with already separated with [SEP] token id inside, couldn't find any function to generate proper token_type_ids.
So, I made a simple function which create proper token_type_ids with padding.
Input : list or tensor / pad_to_multiple_of (target length) / tokenizer (to recognize sep token id and add proper pad token id)
output : tensor of token_type_ids with pad id
Hope this might be used for those who want to override DataCollator class.

Fixes # (issue)


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- [ ] Did you write any new necessary tests?


## Who can review?
- new function for Bert-like models collator : @LysandreJik

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