External editor improvements and fixes

Notable changes:

- Now ScriptLanguages have the option to override the global external editor setting.
If `ScriptLanguage::open_in_external_editor()` returns `ERR_UNAVAILABLE` (which it does by default), then the global external editor option will be used.
- Added formatting to the external editor execution arguments. Now it's possible to write something like this: `{project} -g {file}:{line}:{col}`.
- `VisualScript::get_member_line()` now can return the line of functions (well, it returns the id of the _Function_ node of the function). I guess there is nothing else we can get a "line" from.

Fixes:

- Fixes a bug where `ScriptEditor::script_goto_method()` would not work if the script is not already open in the built-in editor.
- Fixes wrong DEFVAL for `cursor_set_column` and `cursor_set_line` in TextEdit.
- `Script::get_member_line()` now returns -1 ("found nothing") by default.

modules/visual_script/visual_script.cpp

@@ -1073,6 +1073,18 @@ void VisualScript::get_script_property_list(List<PropertyInfo> *p_list) const {
 	}
 }
 
+int VisualScript::get_member_line(const StringName &p_member) const {
+#ifdef TOOLS_ENABLED
+	if (has_function(p_member)) {
+		for (Map<int, Function::NodeData>::Element *E = functions[p_member].nodes.front(); E; E = E->next()) {
+			if (E->get().node->cast_to<VisualScriptFunction>())
+				return E->key();
+		}
+	}
+#endif
+	return -1;
+}
+
 #ifdef TOOLS_ENABLED
 bool VisualScript::are_subnodes_edited() const {
 

modules/visual_script/visual_script.h

@@ -356,6 +356,8 @@ public:
 
 	virtual void get_script_property_list(List<PropertyInfo> *p_list) const;
 
+	virtual int get_member_line(const StringName &p_member) const;
+
 #ifdef TOOLS_ENABLED
 	virtual bool are_subnodes_edited() const;
 #endif

modules/visual_script/visual_script_editor.cpp

@@ -2153,7 +2153,7 @@ void VisualScriptEditor::goto_line(int p_line, bool p_with_error) {
 			_update_graph();
 			_update_members();
 
-			call_deferred("_center_on_node", p_line); //editor might be just created and size might not exist yet
+			call_deferred("call_deferred", "_center_on_node", p_line); //editor might be just created and size might not exist yet
 
 			return;
 		}
@@ -2192,18 +2192,6 @@ void VisualScriptEditor::get_breakpoints(List<int> *p_breakpoints) {
 	}
 }
 
-bool VisualScriptEditor::goto_method(const String &p_method) {
-
-	if (!script->has_function(p_method))
-		return false;
-
-	edited_func = p_method;
-	selected = edited_func;
-	_update_members();
-	_update_graph();
-	return true;
-}
-
 void VisualScriptEditor::add_callback(const String &p_function, PoolStringArray p_args) {
 
 	if (script->has_function(p_function)) {

modules/visual_script/visual_script_editor.h

@@ -244,7 +244,6 @@ public:
 	virtual void tag_saved_version();
 	virtual void reload(bool p_soft);
 	virtual void get_breakpoints(List<int> *p_breakpoints);
-	virtual bool goto_method(const String &p_method);
 	virtual void add_callback(const String &p_function, PoolStringArray p_args);
 	virtual void update_settings();
 	virtual void set_debugger_active(bool p_active);