Add IterableDataset.filter
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['The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_3826). All of your documentation changes will be reflected on that endpoint.'
 "Indeed ! If `batch_size` is `None` or `<=0` then the full dataset should be passed. It's been mentioned in the docs for a while but never actually implemented. We can fix that later"]
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_Needs https://github.com/huggingface/datasets/pull/3801 to be merged first_

I added `IterableDataset.filter` with an API that is a subset of `Dataset.filter`:
```python
def filter(self, function, batched=False, batch_size=1000, with_indices=false, input_columns=None):
```

TODO:
- [x] tests
- [x] docs

related to https://github.com/huggingface/datasets/issues/3444 and https://github.com/huggingface/datasets/issues/3753
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