DRILL-6744: Support varchar and decimal push down
1. Added enableStringsSignedMinMax parquet format plugin config and store.parquet.reader.strings_signed_min_max session option to control reading binary statistics for files generated by prior versions of Parquet 1.10.0.
2. Added ParquetReaderConfig to store configuration needed during reading parquet statistics or files.
3. Provided mechanism to enable varchar / decimal filter push down.
4. Added VersionUtil to compare Drill versions in string representation.
5. Added appropriate unit tests.
closes #1537
