DRILL-4291: Fix Missing classes when trying to query varchar[] using JDBC
- Create a new simplified version of the Hadoop Text class that doesn't include massive dependencies.
- Update Vectors to use new Text class.
- Update the jdbc-all module to have a test which also includes complex types.
- Clean up exclusions in Jdbc jar file to reduce file size.
- Add an enforcer rule that ensures the adbc-all jar exclusions are maintained in the future.
This closes #336.
