Currently the codegen includes some arrow headers into our own headers. This is unfortunate since it drags in arrow into the user's global namespace when we could avoid it fairly easily. The main issues are:

• utility functions on generated headers that are needed by aren't useful to the user (ideally we only expose to_data_cell which returns our own type)
• arrow::Result/arrow::Status - we should have a different error value

We should strive to more clearly separate concerns

Note that we can't avoid dragging in arrow itself for building the SDK (and binary distribution of the C++ SDK remains very challenging as we depend on C++ standard library types which are notoriously poisonous to binary interfaces)