Support model info lookup using aircraft model.
Added flap/slat lever mappings.
Update model information implementation.

- Similar functions now return data in a common format.
- Fully document each of the mappings that are defined.
- Added comprehensive tests for functions and mapping integrity.
- Fixed some broken values caused by copy and pasting.
Fallback to get_flap_map() in get_lever_map().
Fallback to get_flap_map() in get_lever_angles()