[data] add validation for shuffle arg

[matthewdeng]

Why are these changes needed?

Add validation for shuffle argument. Previously, specifying an incorrect argument would lead to the default behavior of None, which does is no shuffling.

Before:

>>> ray.data.read_parquet("/tmp/files", shuffle=True)
Dataset(num_rows=?, schema={})

After:

>>> ray.data.read_parquet("/tmp/files", shuffle=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/matt/workspace/ray/python/ray/data/read_api.py", line 768, in read_parquet
    datasource = ParquetDatasource(
                 ^^^^^^^^^^^^^^^^^^
  File "/Users/matt/workspace/ray/python/ray/data/_internal/datasource/parquet_datasource.py", line 284, in __init__
    _validate_shuffle_arg(shuffle)
  File "/Users/matt/workspace/ray/python/ray/data/datasource/file_based_datasource.py", line 527, in _validate_shuffle_arg
    raise ValueError(
ValueError: Invalid value for 'shuffle': True. Valid values are None, 'files'.

Related issue number

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[matthewdeng]

I wasn't sure what the best way to organize this was, I expected ParquetDatasource to extend FileBasedDatasource.

[bveeramani]

They have different code paths because ParquetDatasource leverages PyArrow's ParquetDataset

[bveeramani]

They have different code paths because ParquetDatasource leverages PyArrow's ParquetDataset