[WIP][SPARK-2406][SQL] Initial support for using ParquetTableScan to read HiveMetaStore tables.

This PR adds an experimental flag `spark.sql.hive.convertMetastoreParquet` that when true causes the planner to detects tables that use Hive's Parquet SerDe and instead plans them using Spark SQL's native `ParquetTableScan`.
Will that causes performance issue if there are lots of partitions?