Implement applyEdit in LSP for signal connecting

modules/gdscript/language_server/gdscript_workspace.h

@@ -60,6 +60,8 @@ protected:
 
 	void list_script_files(const String &p_root_dir, List<String> &r_files);
 
+	void apply_new_signal(Object *obj, String function, PackedStringArray args);
+
 public:
 	String root;
 	String root_uri;