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.cpp

@@ -145,6 +145,12 @@ namespace BlackMisc
             m_callsign = "BROADCAST";
         }
 
+        void CCallsign::markAsWallopCallsign()
+        {
+            m_callsignAsSet = "SUP";
+            m_callsign = "SUP";
+        }
+
         bool CCallsign::isMaybeCopilotCallsign(const CCallsign &pilotCallsign) const
         {
             return  m_callsign.startsWith(pilotCallsign.asString()) &&