[T5Tokenizer] fix t5 token type ids
Author: patrickvonplaten
Pull request: yes

# What does this PR do?

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Fixes #7840

T5 does not use token type ids. Nevertheless, the T5Tokenizer should analogs to RobertaTokenizer return all [0] for the `token_type_ids`.

Functions and Tests are added for T5TokenizerFast and T5Tokenizer.


## Before submitting
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 albert, bert, XLM: @LysandreJik
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 tokenizers: @mfuntowicz
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 Benchmarks: @patrickvonplaten
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 examples/distillation: @VictorSanh
 nlp datasets: [different repo](https://github.com/huggingface/nlp)
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