Gui: temporary fix of preference menu in macos

QAction defaults menu role to TextHeuristicRole, which causes qt to
guess the menu role based on action title. And titles start with
'Config', 'Options', 'Settings', etc. will be considered as preference
menu. It seems some non-english translation causes the wrong action be
chosen as preference, such as 'Treeview actions'.

This commit just applied a temporary fix to default to QAction::NoRole
for GroupCommand. If there is ever some GroupCommand need to be a
system menu item on macos, we could add some command bit flag for that
purpose.

src/Gui/Action.cpp

@@ -252,8 +252,10 @@ void ActionGroup::addTo(QWidget *w)
     // and adding this action to the widget doesn't work.
     if (_dropDown) {
         if (w->inherits("QMenu")) {
-            QMenu* menu = qobject_cast<QMenu*>(w);
-            menu = menu->addMenu(_action->text());
+            QMenu *menu = new QMenu(w);
+            QAction* action = qobject_cast<QMenu*>(w)->addMenu(menu);
+            action->setMenuRole(_action->menuRole());
+            menu->setTitle(_action->text());
             menu->addActions(_group->actions());
         }
         else if (w->inherits("QToolBar")) {

src/Gui/Command.cpp

@@ -995,6 +995,7 @@ Command *GroupCommand::addCommand(const char *name) {
 
 Action * GroupCommand::createAction(void) {
     ActionGroup* pcAction = new ActionGroup(this, getMainWindow());
+    pcAction->setMenuRole(QAction::NoRole);
     pcAction->setDropDownMenu(true);
     pcAction->setExclusive(false);
     pcAction->setCheckable(true);

src/Gui/CommandStd.cpp

@@ -377,6 +377,7 @@ Action * StdCmdDlgPreferences::createAction(void)
 {
     Action *pcAction = Command::createAction();
     pcAction->setMenuRole(QAction::PreferencesRole);
+
     return pcAction;
 }