Add: [Script] ScriptCargo::GetName, to get the human readable name of a cargo (#8544)

Of course this translates into AICargo.GetName() for AIs and
GSCargo.GetName() for GameScripts.

src/script/api/script_cargo.hpp

@@ -84,6 +84,14 @@ public:
 	 */
 	static bool IsValidTownEffect(TownEffect towneffect_type);
 
+	/**
+	 * Get the name of the cargo type.
+	 * @param cargo_type The cargo type to get the name of.
+	 * @pre IsValidCargo(cargo_type).
+	 * @return The name of the cargo type.
+	 */
+	static char *GetName(CargoID cargo_type);
+
 	/**
 	 * Gets the string representation of the cargo label.
 	 * @param cargo_type The cargo to get the string representation of.