[SPARK-9095] [SQL] Removes the old Parquet support

This PR removes the old Parquet support:

- Removes the old `ParquetRelation` together with related SQL configuration, plan nodes, strategies, utility classes, and test suites.

- Renames `ParquetRelation2` to `ParquetRelation`

- Renames `RowReadSupport` and `RowRecordMaterializer` to `CatalystReadSupport` and `CatalystRecordMaterializer` respectively, and moved them to separate files.

  This follows naming convention used in other Parquet data models implemented in parquet-mr. It should be easier for developers who are familiar with Parquet to follow.

There's still some other code that can be cleaned up. Especially `RowWriteSupport`. But I'd like to leave this part to SPARK-8848.

Author: Cheng Lian <lian@databricks.com>

Closes #7441 from liancheng/spark-9095 and squashes the following commits:

c7b6e38 [Cheng Lian] Removes WriteToFile
2d688d6 [Cheng Lian] Renames ParquetRelation2 to ParquetRelation
ca9e1b7 [Cheng Lian] Removes old Parquet support