[C++][Parquet] Page statistics not written in v2?

While working in integration tests of parquet2 against pyarrow, I noticed that page statistics are only written by pyarrow when using version 1.

I do not have an easy way to reproduce this within pyarrow as I am not sure how to access individual pages from a column chunk, but it is something that I observe when trying to integrate.

The row group stats are still written, this only affects page statistics.

pyarrow call:

```
pa.parquet.write_table(
t,
path,
version="2.0",
data_page_version="2.0",
write_statistics=True,
)
```

changing version to "1.0" does not impact this behavior, suggesting that the specific option causing this behavior is the data_page_version="2.0".

**Reporter**: [Jorge Leitão](https://issues.apache.org/jira/browse/ARROW-13240) / @jorgecarleitao

_{**Note**: *This issue was originally created as [ARROW-13240](https://issues.apache.org/jira/browse/ARROW-13240). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

Start from the pyarrow.parquet.write_table call in the report and reproduce the difference between data_page_version="1.0" and "2.0" with write_statistics enabled. Compare page statistics with the row-group statistics, and consider the issue complete when v2 data pages preserve page statistics as expected.

Written by the indexing model from the issue text.