Implement more plugins about dask-sql HOT 1 OPEN

Some information on how to tackle such a task:

1. Make sure to understand what the class does. This can be done by looking up the definition in the Apache Calcite source doe.
2. Build a SQL statement use case for it and debug it in the dask-sql command line tool, with debug turned on. This will give you the full generated algebra and where exactly you still need to implement something.
3. Add a new plugin in the rel/logical folder of dask_sql and also register it at the context.
4. For testing, maybe add a code.interact(local=locals()) instead of a real convert function and find out, which parameters the java instance has. Then implement the logic with Dask API calls. Have a look into other plugins.
5. Create some tests and do a PR :-)

from dask-sql.