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/DDS/DdsUnitTests/initialisation.cpp

@@ -14,7 +14,7 @@ Initialisation::Initialisation() : m_domainParticipant(nullptr)
   , m_ddsSubscriber(nullptr)
   , m_subListener(new DDSGeneric::SubscriberListener)
   .getNGLLogger("UnitTests.Initialisation")),
-    m_logger(NGL::NGLLoggerBootstrap::getLogger())
+    m_logger(NGL::NGLLoggerBootstrap::getNGLRootLogger())
 {
     if (!DDS::QosProfile::setDefault())
         ERROR_LOG(m_logger) << "Error setting default QoS from xml-file ";