[Generate] Add save mode logits processor to remove nans and infs if necessary
Author: patrickvonplaten
Pull request: yes

# What does this PR do?

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It can happen that the output logits of models contain `inf` or even `nan` values. Those values will necessarily lead to errors when using the `sample(...)` or `beam_sample(...)` method. 

This PR adds an optional `InfNanRemoveLogitsProcessor` that - enabled - should remove those values. It should help to fix flaky ci failures like this one: https://app.circleci.com/pipelines/github/huggingface/transformers/21081/workflows/36711d05-4282-4167-88df-59fbda03fe33/jobs/181274

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/master/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
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      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/master/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors which may be interested in your PR.

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Models:

- albert, bert, xlm: @LysandreJik
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- tensorflow: @jplu

Library:

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- ray/raytune: @richardliaw, @amogkam
- text generation: @patrickvonplaten
- tokenizers: @n1t0, @LysandreJik
- trainer: @sgugger
- pipelines: @LysandreJik

Documentation: @sgugger

HF projects:

- nlp datasets: [different repo](https://github.com/huggingface/nlp)
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