As a follow up of voice testing

* allow to directly go from ATC component to audio component (control volume)
* reordered keypad a bit
* audio setup, "private slots" -> "private"

src/blackgui/components/atcstationcomponent.h

@@ -74,6 +74,9 @@ namespace BlackGui
             //! Request a text message
             void requestTextMessageWidget(const BlackMisc::Aviation::CCallsign &callsign);
 
+            //! Request audio widget
+            void requestAudioWidget();
+
         private:
             //! \copydoc Models::CAtcStationListModel::changedAtcStationConnectionStatus
             void changedAtcStationOnlineConnectionStatus(const BlackMisc::Aviation::CAtcStation &station, bool added);