Automatically scroll the SettingsView to ensure the focused item is visible

Also removed old manual scrolling code from SdlGamepadKeyNavigation as it was broken on Qt 6 anyway.

app/gui/sdlgamepadkeynavigation.h

@@ -24,7 +24,6 @@ public:
 
 private:
     void sendKey(QEvent::Type type, Qt::Key key, Qt::KeyboardModifiers modifiers = Qt::NoModifier);
-    void sendWheel(QPoint& angleDelta);
 
 private slots:
     void onPollingTimerFired();