Added unit tests for status message and property index sorting

tests/blackmisc/testpropertyindex.h

@@ -30,6 +30,9 @@ namespace BlackMiscTest
     private slots:
         //! Simulated aircraft index checks
         void propertyIndexCSimulatedAircraft();
+
+        //! Sorting based on property index
+        void propertyIndexSort();
     };
 } // namespace