bug-fix: set menu role for certain actions

On macOS, OS will try to merge some actions to the application menu by
text matching, which will be broken in Chinese. So we need to set these
actions' role specifically, including: settings, exit, about, about QT.

src/vmainwindow.cpp

@@ -347,11 +347,13 @@ void VMainWindow::initHelpMenu()
 
     QAction *aboutAct = new QAction(tr("&About VNote"), this);
     aboutAct->setToolTip(tr("View information about VNote"));
+    aboutAct->setMenuRole(QAction::AboutRole);
     connect(aboutAct, &QAction::triggered,
             this, &VMainWindow::aboutMessage);
 
     QAction *aboutQtAct = new QAction(tr("About &Qt"), this);
     aboutQtAct->setToolTip(tr("View information about Qt"));
+    aboutQtAct->setMenuRole(QAction::AboutQtRole);
     connect(aboutQtAct, &QAction::triggered,
             qApp, &QApplication::aboutQt);
 
@@ -537,6 +539,7 @@ void VMainWindow::initFileMenu()
     QAction *settingsAct = newAction(QIcon(":/resources/icons/settings.svg"),
                                      tr("&Settings"), this);
     settingsAct->setToolTip(tr("View and change settings for VNote"));
+    settingsAct->setMenuRole(QAction::PreferencesRole);
     connect(settingsAct, &QAction::triggered,
             this, &VMainWindow::viewSettings);
 
@@ -548,6 +551,7 @@ void VMainWindow::initFileMenu()
     QAction *exitAct = new QAction(tr("&Exit"), this);
     exitAct->setToolTip(tr("Exit VNote"));
     exitAct->setShortcut(QKeySequence("Ctrl+Q"));
+    exitAct->setMenuRole(QAction::QuitRole);
     connect(exitAct, &QAction::triggered,
             this, &VMainWindow::close);