BUILD_RTI DDS Module Guard Fixes

- Add missing m_logger member declarations to GenericDataWriter,
  GenericDataReader, GenericDtcImplSubscriberTemplate
- Add DynamicDataImpl.hpp include for complete type in publisher.h/cpp
- Wrap dds_connector.cpp implementation in #if BUILD_RTI guards
- Fix stub signatures in dds_connector.h to match implementation
- Set CMAKE_CXX_STANDARD to 17 (RTI 7.7.0 hard requirement)

RTI Connext DDS 7.7.0 only supports C++14/C++17. C++20/23 causes
header compilation errors. Cannot mix C++ variants.

Remaining Qt6 issues (separate from RTI work):
- QJsonDocument::toBinaryData/fromBinaryData → toJson/fromJson
- QJsonObject initializer list syntax in training_area_telegrams.cpp

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

qt6-after/qt6-migrated-legatus/Lts/DDS/DDSConnector/dds_connector.cpp

@@ -2,6 +2,8 @@
 
 #include "dds_connector.h"
 
+#if BUILD_RTI
+
 #include "publisher.h"
 #include "subscriber.h"
 
@@ -250,3 +252,5 @@ void DdsConnector::createWaitSetHandler()
 }
 
 } // namespace DDSConnector
+
+#endif // BUILD_RTI