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.*}

Inizia da parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java, in readNextFilteredRowGroup(), quindi confronta la logica hasNext() dell’iteratore nella modifica Iceberg collegata. Traccia il modo in cui avanza un row group con rowCount 0 e determina come il conteggio dei record ignorati debba arrivare al chiamante; il lavoro è completo quando i chiamanti possono determinare in modo affidabile se rimangono record dopo il filtraggio di ColumnIndex.

Scritto dal modello di indicizzazione a partire dal testo della issue.