Qt6 Migration: BUILD_RTI guards und CMake fixes

- BUILD_RTI conditional compilation für RTI Connext DDS dependencies
- Namespace fixes in core_dtc.h (Core:: → DDS::Core::)
- CMakeLists.txt: BUILD_RTI option und conditional dependencies
- Handler minelayer: namespace closing mit BUILD_RTI guard
- Build erfolgreich mit BUILD_RTI=OFF validiert

Signed-off-by: Torsten Wierschin <torsten.wierschin@life-maps.com>

qt6-after/qt6-migrated-legatus/Lts/Services/VideoOverlayManagement/main_handler.h

@@ -9,6 +9,7 @@
 #pragma once
 
 #include <QtCore/QObject>
+#include <QTimer>
 
 #include "avs_interface.h"
 #include "handler_participant_data.h"
@@ -17,8 +18,6 @@
 #include "dds_handler.h"
 #include "logger.h"
 
-class QTimer;
-
 namespace VideoOverlayManagement
 {
 // Forwarddeclarations
@@ -57,7 +56,9 @@ NGL::INGLLogger &m_logger;
   int m_exerciseId;                                                       ///< Exercise id
   AvsInterface                              *m_avsIf;                     ///< Pointer to AVS-Interface
   AvsIfConnectionState                       m_avsConnectionState;        ///< AVS connection state
+#if BUILD_RTI
   std::shared_ptr<DdsHandler>                m_ddsHandler;                ///< Pointer to DDS handler
+#endif
   std::shared_ptr<HandlerParticipantData>    m_handlerParticipantData;    ///< Pointer to participant data handler
   std::shared_ptr<HandlerInfrastructureData> m_handlerInfrastructureData; ///< Pointer to infrastructure data handler
   std::unique_ptr<HandlerOverlays>           m_handlerOverlays;           ///< Pointer to overlay handler