Remove RES and REF typedefs in favor of spelled out Ref<>

These typedefs don't save much typing compared to the full `Ref<Resource>`
and `Ref<RefCounted>`, yet they sometimes introduce confusion among
new contributors.

editor/inspector_dock.h

@@ -118,7 +118,7 @@ class InspectorDock : public VBoxContainer {
 
 	void _warning_pressed();
 	void _resource_created();
-	void _resource_selected(const RES &p_res, const String &p_property);
+	void _resource_selected(const Ref<Resource> &p_res, const String &p_property);
 	void _edit_forward();
 	void _edit_back();
 	void _menu_collapseall();