ColumnIndex should provide number of records skipped

When integrating Parquet ColumnIndex, I found we need to know from Parquet that how many records that we skipped due to ColumnIndex filtering. When rowCount is 0, readNextFilteredRowGroup() just advance to next without telling the caller. See code here

In Iceberg, it reads Parquet record with an iterator. The hasNext() has the following code():

valuesRead + skippedValues < totalValues

See ( 

So without knowing the skipped values, it is hard to determine hasNext() or not. 

Currently, we can workaround by using a flag. When readNextFilteredRowGroup() returns null, we consider it is done for the whole file. Then hasNext() just retrun false. 

**Reporter**: [Xinli Shang](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=shangxinli) / @shangxinli
**Assignee**: [Xinli Shang](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=shangx@uber.com) / @shangxinli

_{**Note**: *This issue was originally created as [PARQUET-1927](https://issues.apache.org/jira/browse/PARQUET-1927). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java の readNextFilteredRowGroup() から始め、リンクされた Iceberg の変更にある iterator の hasNext() ロジックと比較します。rowCount 0 の row group がどのように進むかを追跡し、スキップされたレコード数がどのように caller に届くべきかを判断します。完了とは、ColumnIndex filtering の後にレコードが残っているかどうかを caller が確実に判断できることです。

索引モデルが issue の本文から書いたものです。