Removed knockout debug UI
Overhauled vehicle modules and APIs

Core now only contains the core components for vehicle creation,
destruction and some basic mechanics.

Interact contains vehicle area (sphere) creation and handles interacting
with nearby vehicles.

Trunk handles vehicle trunks and uses the Interact API to allow them to
be opened by interacting with the vehicle.

VehicleTypeIndex is renamed to VehicleType. Removed CreateVehicleOfType
and some other per-vehicle fields from this module. CreateWorldVehicle
is now used to create vehicles (which is in Core).

Vehicles spawned by the server are now referred to as Loot Vehicles.
Modules and functions renamed appropriately.

All vehicle data is now private and other modules have been converted to
use correct interfaces.

Overall this overhaul will make vehicle modules easier to write, manage
and hook into other functionality.