Change: Decouple and remove landscape-dependent cargo types. (#11719)

Cargo types of default engines, industries and houses are now specified in terms of label.

src/roadveh_cmd.cpp

@@ -286,6 +286,7 @@ CommandCost CmdBuildRoadVehicle(DoCommandFlag flags, TileIndex tile, const Engin
 
 		v->spritenum = rvi->image_index;
 		v->cargo_type = e->GetDefaultCargoType();
+		assert(IsValidCargoID(v->cargo_type));
 		v->cargo_cap = rvi->capacity;
 		v->refit_cap = 0;