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/Generic/generic_base.h

@@ -6,6 +6,11 @@
 #include <string>
 #include <ddsgen_export.h>
 
+#if BUILD_RTI
+#include <dds/topic/topic.hpp>
+#include <rti/core/xtypes/DynamicTypeImpl.hpp>
+#endif
+
 class QObject;
 class QMetaMethod;
 
@@ -26,6 +31,8 @@ struct topic_type_name {
 #endif
     }
 };
+
+#if BUILD_RTI
 template<>
 struct topic_type_name<dds::core::xtypes::DynamicData> {
     static std::string value() {