Linkgraph: Use sparse storage format for edge annotations

Copy relevant parts of base edge into edge annotation

src/linkgraph/mcf.h

@@ -89,11 +89,4 @@ public:
 	virtual ~MCFHandler() {}
 };
 
-inline bool IsLinkGraphCargoExpress(CargoID cargo)
-{
-	return IsCargoInClass(cargo, CC_PASSENGERS) ||
-			IsCargoInClass(cargo, CC_MAIL) ||
-			IsCargoInClass(cargo, CC_EXPRESS);
-}
-
 #endif /* MCF_H */