Feature/3139 new features for tips (#3152)

* "Tip of the Day" option added to Help menu

* Tip of the Day setting moved

* If no new tips are availabe, don't show tip of the day again

* list storing try #1

* first unseen tip shown first

* lastShownTip removed

* fixed next/previous buttons

* spaces > tab

* "Show this window on startup" is not checked by default

cockatrice/src/dlg_tip_of_the_day.h

@@ -21,6 +21,7 @@ public:
     explicit DlgTipOfTheDay(QWidget *parent = nullptr);
     ~DlgTipOfTheDay() override;
     bool successfulInit;
+    bool newTipsAvailable;
 signals:
     void newTipRequested(int tipId);