[C++][Parquet] Page header does not save statistics once page index is enabled

[wgtmac]

Describe the enhancement requested

Once writing page index is supported, we should not save page statistics in the data page header as it is duplicated.

Although page stats is disabled by parquet-mr globally (link), we cannot do that because a lot of test cases in the parquet-cpp relies on the stats from page header.

Component(s)

C++, Parquet