Add after_destruct and cache the existence of on_construct, on_destruct and after_destruct for quick skipping when a node does not have them

src/nodedef.cpp

@@ -117,6 +117,9 @@ void ContentFeatures::reset()
 	visual_solidness = 0;
 	backface_culling = true;
 #endif
+	has_on_construct = false;
+	has_on_destruct = false;
+	has_after_destruct = false;
 	/*
 		Actual data