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ARROW-13763: [Python] Close files in ParquetFile & ParquetDatasetPiece (#13821)

Will fix [ARROW-13763](https://issues.apache.org/jira/browse/ARROW-13763)

A separate Jira issue will be made to address closing files in V2 ParquetDataset, which needs to be handled in the C++ layer. 

Adds context manager to `pq.ParquetFile` to close input file, and ensure reads within `pq.ParquetDataset` and `pq.read_table` are closed.

```python

# user opened file-like object will not be closed
with open('file.parquet', 'rb') as f:
    with pq.ParquetFile(f) as p:
        table = p.read()
        assert not f.closed  # did not inadvertently close the open file
        assert not p.closed
    assert not f.closed      # parquet context exit didn't close it
    assert not p.closed      # references the input file status
assert f.closed              # normal context exit close
assert p.closed              # ...

# path-like will be closed upon exit or `ParquetFile.close`
with pq.ParquetFile('file.parquet') as p:
    table = p.read()
    assert not p.closed
assert p.closed
```

Authored-by: Miles Granger <miles59923@gmail.com>
Signed-off-by: Antoine Pitrou <antoine@python.org>