Adds a from_huggingface method to Datasets, which allows the conversion of a Hugging Face Dataset to a Ray Dataset. As a Hugging Face Dataset is backed by an Arrow table, the conversion is trivial.
Adds a streaming based reading option for Snappy-compressed files. Arrow doesn't support streaming Snappy decompression since the canonical C++ Snappy library doesn't natively support streaming decompression. This PR works around this by doing streaming reads of snappy-compressed files using the streaming decompression API provided in the [python-snappy](https://github.com/andrix/python-snappy) package.
This commit supplies a custom datasource that uses Arrow + [python-snappy](https://github.com/andrix/python-snappy) to read and decompress Snappy-compressed files.
Co-authored-by: siddharth.goel <siddharth.goel@bytedance.com>
Co-authored-by: Chen Shen <scv119@gmail.com>
