Increase json reader block_size automatically
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Currently some files can't be read with the default parameters of the JSON lines reader.
For example this one:
https://huggingface.co/datasets/thomwolf/codeparrot/resolve/main/file-000000000006.json.gz

raises a pyarrow error:
```python
ArrowInvalid: straddling object straddles two block boundaries (try to increase block size?)
```

The block size that is used is the default one by pyarrow (related to this [jira issue](https://issues.apache.org/jira/browse/ARROW-9612)).

To fix this issue I changed the block_size to increase automatically if there is a straddling issue when parsing a batch of json lines.

By default the value is `chunksize // 32` in order to leverage multithreading, and it doubles every time a straddling issue occurs. The block_size is then reset for each file.

cc @thomwolf @albertvillanova 
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