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/function_topic_tests.cpp

@@ -25,7 +25,7 @@ int main(int argc, char* argv[])
 
 FunctionTopicTests::FunctionTopicTests() : m_mainThreadId(QThread::currentThreadId())
   .getNGLLogger("UnitTests.FunctionTopicTests")),
-    m_logger(NGL::NGLLoggerBootstrap::getLogger())
+    m_logger(NGL::NGLLoggerBootstrap::getNGLRootLogger())
 {
     qRegisterMetaType<DdsUnitTests::FunctionReply>("DdsUnitTests::FunctionReply");
     qRegisterMetaType<DdsUnitTests::FunctionReplyWithState>("DdsUnitTests::FunctionReplyWithState");