DRILL-7096: Develop vector for canonical Map<K,V>
- Added new type DICT;
- Created value vectors for the type for single and repeated modes;
- Implemented corresponding FieldReaders and FieldWriters;
- Made changes in EvaluationVisitor to be able to read values from the map by key;
- Made changes to DrillParquetGroupConverter to be able to read Parquet's MAP type;
- Added an option `store.parquet.reader.enable_map_support` to disable reading MAP type as DICT from Parquet files;
- Updated AvroRecordReader to use new DICT type for Avro's MAP;
- Added support of the new type to ParquetRecordWriter.
