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/ServiceManagement/group_handler.h

@@ -0,0 +1,89 @@
+/**
+  * The GroupHandler class handles all group related classes and writes the groups state to DDS.
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Hannes Baeuerle, SLSE, 2016-02-15
+  */
+
+#pragma once
+
+#include <QObject>
+#include <QSet>
+#include <QVector>
+
+#include "logger.h"
+#include "dds_handler.h"
+#include "group.h"
+
+namespace ServiceManagement
+{
+class HeartbeatListener;
+class ServiceDonator;
+
+struct GroupScheme
+{
+  const Core::ServiceGroupType groupType;
+  const QString                groupName;
+  QSet<int>                    services;
+
+  explicit GroupScheme(Core::ServiceGroupType type, const QString &name) : groupType(type) , groupName(name) {}
+
+  void addServiceId(int serviceId)
+  {
+    services += serviceId;
+  }
+};
+
+class GroupHandler final
+  : public QObject
+  , protected Interface::Fts::StartGroupRequestHandler
+  , protected Interface::Fts::StopGroupRequestHandler
+  , protected Interface::Fts::RestartGroupRequestHandler
+{
+  Q_OBJECT
+public:
+  explicit GroupHandler(const std::shared_ptr<DdsHandler> &ddsHandler,
+                        const std::shared_ptr<ServiceDonator> &donator);
+  ~GroupHandler();
+
+  bool init(int32_t coreDomain);
+
+  void addServiceLink(int serviceId, Core::ServiceGroupType groupType);
+
+  QVector<Group *> groups() const;
+
+  virtual void onStartGroupRequest(const rti::core::SampleIdentity &cookie,
+                                   const GroupRequest &request) override final;
+  virtual void onStopGroupRequest(const rti::core::SampleIdentity &cookie,
+                                  const GroupRequest &request) override final;
+  virtual void onRestartGroupRequest(const rti::core::SampleIdentity &cookie,
+                                     const GroupRequest &request) override final;
+public Q_SLOTS:
+  void slotStartGroupRequest(const GroupRequest &request);
+  void slotStopGroupRequest(const GroupRequest &request);
+Q_SIGNALS:
+  void startGroupReply(const Core::FunctionReplyObject &reply);
+  void stopGroupReply(const Core::FunctionReplyObject &reply);
+private:
+  Core::FunctionReplyObject onStartGroup(const GroupRequest &request);
+  Core::FunctionReplyObject onStopAllForExercise(int domainId, int exercisePartitionId);
+  Core::FunctionReplyObject onStopGroup(const GroupRequest &request);
+  Core::FunctionReplyObject onRestartGroup(const GroupRequest &request);
+private: // methods
+  GroupScheme *groupSchemeFromType(Core::ServiceGroupType type);
+  Group *getGroup(const GroupRequest &groupToFind) const;
+  Group *getSimilarGroup(const GroupRequest &groupToFind) const;
+  bool startGroupCore(int32_t domainId);
+
+private: // attributes
+  QVector<GroupScheme *>         m_groupSchemes;
+  QVector<Group *>               m_groups;
+  std::shared_ptr<ServiceDonator>m_serviceDonator;
+  std::shared_ptr<DdsHandler>    m_ddsHandler;
+  HeartbeatListener             *m_heartbeatListener;
+  LOGGER_T                       m_logger;
+
+  static qint64 groupIdCounter;
+};
+} // namespace ServiceManagement