Complete PrtCnv Qt6 migration so CoPrtCnv/PrtCnvLib/PrtCnv/ddsview build

Restore dropped m_logger members, QMutex->QRecursiveMutex, splitView->split, error->errorOccurred (migration-only, verified vs legacy).

qt6-after/qt6-migrated-legatus/TetraIF/PrtCnv/PrtCnvRadioTrafficThread.cpp

@@ -31,7 +31,7 @@ PrtCnvRadioTrafficThread::PrtCnvRadioTrafficThread(PrtCnvThreadStarter* a_parent
   , m_hystLoad(5)
   , m_calcTimeout(1000)
   , m_cleanupTimeout(5000)
-  , m_mutex(QMutex::Recursive)
+  , m_mutex()
 {}
 
 void PrtCnvRadioTrafficThread::newTelegramArrived(unsigned int size)