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/AudioVideoManagement/main_handler.cpp

@@ -37,7 +37,7 @@
 using namespace AudioVideoManagement;
 
 MainHandler::MainHandler(QObject *parent) : QObject(parent),
-    m_logger(NGL::NGLLoggerBootstrap::getLogger()) {}
+    m_logger(NGL::NGLLoggerBootstrap::getNGLRootLogger()) {}
 
 MainHandler::~MainHandler() = default;