Add HyperLogLog / CountMinSketch to parquet statistics

HLL and CMS for rowgroups could help with query planning (getting a sense of data skew) and with cheaply counting approximate distinct values. Both are commutative which means they can be combined across rowgroups (unlike an exact distinct count for example).

**Reporter**: [Alex Levenson](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=alexlevenson) / @isnotinvain

_{**Note**: *This issue was originally created as [PARQUET-42](https://issues.apache.org/jira/browse/PARQUET-42). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start by reviewing how Parquet statistics are represented for rowgroups and how those statistics are consumed during query planning. The issue provides no file or test entry point; done means supporting HLL and CMS statistics that can be combined across rowgroups for approximate distinct counts and data-skew estimation.

Written by the indexing model from the issue text.