[DF] Validate Rex call logic

[jdye64]

Is your feature request related to a problem? Please describe. Testing, tweaking, repeat needs to happen for the Rex (Row Expression) logic after all of the porting is complete. Rex calls are fundamental to SQL and likewise Dask-SQL. They involve small nuances and therefore should be validated to ensure they are operating as expected. Small mishaps in the rex call logic could cause erroneous output in multiple queries so ensuring the logic is sound is important.

Describe the solution you'd like Pytests passing, human observation on the logic, and multiple user testing sessions to ensure the logic works as expected against real world queries with known behaviors.

Describe alternatives you've considered None

Additional context None