Enable AI helicopters in SDK

Requested immediately after SU11 here: [SU11] Spawn Helicopter as AI?

Per Asobo this is “not planned”. Multiple devs consider this scenario blocking even without having AI takeoff/landing/taxi/flight.

Since we can’t spawn helicopters means that things like VATSIM and JoinFS cannot have helicopters. Asobo made a special fix for their own internal multiplayer but there is no way to spawn a non-user helicopter right now.

We still request the ability to spawn the AI helicopter objects, even if this means there is no way to pilot them other than velocity vars.