Qt6 Migration: Complete migration with DDS/RTI support and build validation

Major Changes:
- Merged latest Qt5 devel content from dlbo (292 files changed, 7 new dirs)
- Consolidated forward-declarations and include folders
- Removed unneeded modules per Niklas' repo check list

Build System Fixes:
- Fixed CMake VERSION_GREATER syntax in ParticipantManagement/CMakeLists.txt
- Added VLC packages (libvlc-dev, vlc-plugin-base) to docker_build.sh
- Added PostgreSQL dev packages (libpq-dev, postgresql-server-dev-all) to Dockerfile
- Fixed locale warnings (ANSI_X3.4-1968 → C.UTF-8)
- Fixed ArcGIS SDK path warnings when BUILD_ARCGIS=OFF

Code Generation Fixes:
- Fixed IDL enum collisions (PortType→CorePortType/DdsutPortType, PdmEventType)
- Fixed Grantlee template svc_translation.cpp.grantlee:
  - Changed {{ idl_enum.name }}_def:: to {{ idl_enum.name }}::
  - Fixed .underlying() calls for C++11 scoped enums (enum class)
- Removed generated files from repo (moc_*, *_dtc.h, *_ftc.h)

Validation:
- BUILD_RTI=ON: SUCCESS
- BUILD_RTI=OFF: SUCCESS
- C++17 standard maintained for RTI 7.7 compatibility
- Ubuntu 26.04 Docker environment verified

Remaining Warnings (expected):
- BgViewer, KDChart, KDReports, Poppler-Qt6 not found (optional features)

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

qt5-before/dlbo/Lts/Services/AudioVideoManagement/dds_handler.h

@@ -0,0 +1,103 @@
+/**
+  * DdsHandler for DDS
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Hanna E. Rathje, SLSE, 2015-09-02
+  */
+#pragma once
+
+#include "logger.h"
+#include <dds/domain/DomainParticipant.hpp>
+#include <DDS/Core/topic_lock_master.h>
+#include <QStringList>
+
+#include <DDS/DDSConnector/dds_connector.h>
+#include <DDS/Core/core_dts_types.h>
+
+#include <AudioVideoManagement/avm_dts.h>
+#include <AudioVideoManagement/avm_fts.h>
+
+#include <boost/optional.hpp>
+
+namespace Core
+{
+class Pacemaker;
+}
+
+namespace DDSConnector
+{
+class DdsConnector;
+}
+
+namespace ExerciseManagement { namespace Interface
+{
+class Dtc;
+}}
+
+namespace InfrastructureManagement { namespace Interface
+{
+class Dtc;
+}}
+
+namespace AssetManagement { namespace Interface
+{
+class Dtc;
+}}
+
+
+namespace AudioVideoManagement
+{
+template<class T>
+boost::optional<T> toBoost(const dds::core::optional<T> &optionalValue)
+{
+  if (!optionalValue.is_set())
+    return boost::none;
+  return optionalValue.get();
+}
+
+class DdsHandler final
+{
+public:
+  explicit DdsHandler(int domainId);
+  ~DdsHandler() = default;
+
+  bool init(const QStringList &qosFileList = QStringList());
+
+  /**
+   * Must be called *after* init and *after* all DTC-consuming instances
+   * have been setup. This is to avoid data races that otherwise could arise
+   * when
+   * - connecting to the onFooChanged() signal and
+   * - shortly after that calling foo() to get all received entities so far.
+   */
+  bool enableDtcClients();
+
+  dds::domain::DomainParticipant   domainParticipant() const;
+
+  std::shared_ptr<Core::Pacemaker>          pacemaker()       const { return m_pacemaker; }
+  std::shared_ptr<Core::TopicLockMaster>    topicLockMaster() const { return m_topicLockMaster; }
+
+  Interface::Dts                           *dts() const       { return m_dts.get(); }
+  Interface::Fts                           *fts() const       { return m_fts.get(); }
+
+  ExerciseManagement::Interface::Dtc       *exmDtc() const    { return m_exmDtc.get(); }
+  InfrastructureManagement::Interface::Dtc *ismDtc() const    { return m_ismDtc.get(); }
+  AssetManagement::Interface::Dtc          *asmDtc() const    { return m_asmDtc.get(); }
+  std::shared_ptr<DDSConnector::DdsConnector> ddsConnector() const { return m_ddsConnector; }
+
+private:
+  std::shared_ptr<DDSConnector::DdsConnector>               m_ddsConnector;
+  std::shared_ptr<Core::Pacemaker>                          m_pacemaker;
+  std::shared_ptr<Core::TopicLockMaster>                    m_topicLockMaster;
+  std::shared_ptr<Interface::Dts>                           m_dts;
+  std::shared_ptr<ExerciseManagement::Interface::Dtc>       m_exmDtc;
+  std::shared_ptr<InfrastructureManagement::Interface::Dtc> m_ismDtc;
+  std::shared_ptr<AssetManagement::Interface::Dtc>          m_asmDtc;
+  std::shared_ptr<Interface::Fts>                           m_fts;
+
+  NGL::INGLLogger          &m_logger;
+};
+
+}
+