Dragging connection from a node socket should open the "Add node" dialog

This is really just a tiny addition that would make node editing a bit more streamlined. So basically as an alternative to pressing shift-a to open the "Add node" dialog in any node editor, dragging a connection from an empty socket onto the empty canvas should open the dialogue as well. Substance Designer does this, and it feels much more fluid, because a lot of the node-editing happens only with the mouse, so why switch to the keyboard just to add one?