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/Proxies/TrainingAreaBaseOC/websocket_handler.cpp

@@ -16,7 +16,7 @@ WebsocketHandler::WebsocketHandler(QObject *parent, int exerciseId,
   , m_exerciseId(exerciseId)
   , m_dtsTaboc(dtsTabOc)
   , m_dtcTaboc(dtcTabOc),
-    m_logger(NGL::NGLLoggerBootstrap::getLogger()) {
+    m_logger(NGL::NGLLoggerBootstrap::getNGLRootLogger()) {
   m_tryConnectionTimer = new QTimer(this);
   connect(m_tryConnectionTimer, &QTimer::timeout, this, &WebsocketHandler::onTryConnectionTimerTimeout);
   m_tryConnectionTimer->start(10 * 1000);