Add feedback when .wallop message is sent

This does the following:
- Opens a message-tab called "SUP" when a .wallop message is sent.
- Throws a validation error if another message is directly send into this "SUP" channel as another .wallop should be used.

src/blackmisc/aviation/callsign.h

@@ -86,6 +86,9 @@ namespace BlackMisc
             //! \remark hack, workaround for VATSIM using "*" as callsign for text messages
             void markAsBroadcastCallsign();
 
+            //! Set a human readable name as "wallop-channel" callsign
+            void markAsWallopCallsign();
+
             //! Returns true if this is a co-pilot callsign of pilot. The logic is that the callsign is the same as the pilot one
             //! but with a single character as suffix.
             //! e.g Pilot logged in as DLH123, observer logged in as DLH123A