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/Plugins/InfrastructureManagement/Data/CMakeLists.txt

@@ -15,6 +15,7 @@ NGL_ADD_LIBRARY(WS IsmDataPlugin MODULE
   ism_foreign_data_plugin.cpp
   ism_foreign_data_plugin.h
 )
+set_target_properties(IsmDataPlugin PROPERTIES AUTOMOC ON)
 NGL_TARGET_LINK_LIBRARIES(IsmDataPlugin
   IsmDataPluginInterface
   IsmShared