Add bindings for "case", "cast", and "trycast" datafusion expr

[jdye64]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
Add bindings for "case", "cast", and "trycast" datafusion expr. These expressions are all similar and need bindings to work with datafusion code.

Describe the solution you'd like
Add bindings for "case", "cast", and "trycast" datafusion expr with a new file in the Python expr module

Describe alternatives you've considered
None

Additional context
None