Re-enable progress on system tray icon (#578)

* Re-enable progress on system tray icon

* fix copy-paste typo in mac sources

* Make tray icon progress optional

* Move tray icon progress setting control to MainWindow

* Move trayicon settings to behavioursettings

Co-authored-by: Yavuz Mert <yavuz.mert@darkbluesystems.net>

src/core/macsystemtrayicon.h

@@ -58,6 +58,7 @@ protected:
 
 private:
   QPixmap normal_icon_;
+  QPixmap grey_icon_;
   std::unique_ptr<MacSystemTrayIconPrivate> p_;
   Q_DISABLE_COPY(MacSystemTrayIcon);
 };