Major Description
In https://github.com/apache/spark/pull/21389, data source schema is validated. However,
- Putting all the process logic together in `DataSourceUtils` is tricky and hard to maintain. On second thought after review, I find that the `OrcFileFormat` in hive package is not matched, so that its validation wrong.
- `DataSourceUtils.verifyWriteSchema` and `DataSourceUtils.verifyReadSchema` is not supposed to be called in every file format. We can move them to some upper entry.
So, I propose we can add a new API `supportDataType` in FileFormat. Each file format can override the method to specify its supported/non-supported data types.
