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/handler_video_receiver.h

@@ -0,0 +1,89 @@
+/**
+  * Handler for all Language HMI objects
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Hanna E. Rathje, SLSE, 2015-09-03
+  */
+#pragma once
+
+#include <QMap>
+#include <QObject>
+
+#include "dds_handler.h"
+#include "logger.h"
+#include "main_handler.h"
+#include <avm_fts.h>
+
+// HTTP Request
+#include <QNetworkAccessManager>
+#include <QTimer>
+
+#include <AudioVideoManagement/avm_db.h>
+
+namespace AudioVideoManagement
+{
+class ObjectVideoReceiver;
+class HandlerVideoReceiver : public QObject
+  , protected Interface::Fts::VideoReceiverModifyRequestHandler
+  , protected Interface::Fts::VideoReceiverModifyActiveRequestHandler
+  , protected Interface::Fts::VideoReceiverModifyAvsRequestHandler
+  , protected Interface::Fts::VideoReceiverRemoveRequestHandler
+{
+  Q_OBJECT
+public:
+  HandlerVideoReceiver(MainHandler *mainHandler,
+                       Interface::Dts *dts,
+                       Interface::Fts *fts,
+                       DatabaseInterface *db);
+
+  ~HandlerVideoReceiver();
+
+  bool init();
+
+private slots:
+  void onGetStatus();
+  void onHttpFinished(QNetworkReply *reply);
+
+private:
+  void onVideoReceiverModifyRequest(const rti::core::SampleIdentity &cookie,
+                                    const VideoReceiverModifyRequest &request) override;
+  void onVideoReceiverModifyActiveRequest(const rti::core::SampleIdentity &cookie,
+                                          const VideoReceiverModifyActiveRequest &request) override;
+  void onVideoReceiverModifyAvsRequest(const rti::core::SampleIdentity &cookie,
+                                       const VideoReceiverModifyAvsRequest &request) override;
+  void onVideoReceiverRemoveRequest(const rti::core::SampleIdentity &cookie,
+                                    const Core::RemoveElementRequest &request) override;
+  Core::FunctionReplyObject videoReceiverCreateRequest(const VideoReceiverModifyRequest &request);
+  Core::FunctionReplyObject videoReceiverModifyRequest(const VideoReceiverModifyRequest &request);
+  Core::FunctionReplyObject videoReceiverModifyActiveRequest(const VideoReceiverModifyActiveRequest &request);
+  Core::FunctionReplyObject videoReceiverModifyAvsRequest(const VideoReceiverModifyAvsRequest &request);
+
+  VideoReceiver convert(const VideoReceiverModifyRequest &request);
+  VideoReceiver convertActive(const VideoReceiverModifyActiveRequest &request);
+  VideoReceiver convertAvs(const VideoReceiverModifyAvsRequest &request);
+
+  void startRequest(const QUrl &requestedUrl);
+  void updateObject(const int key, const double powerLevel, const double snr, const bool lockstatus, const int frequency);
+  void activateChannel(const int channelId, const bool activate);
+  void checkActiveState(const int key, const int remuxInputMask);
+
+  void onSendHttpRequest(const int key);
+
+private:
+  QMap<int, ObjectVideoReceiver *>           m_videoReceiverObjMap; // Key = id VideoReceiver
+  MainHandler                               *m_mainHandler;
+  Interface::Dts       *m_dts;
+  Interface::Fts       *m_fts;
+  DatabaseInterface    *m_db;
+
+  // HTTP Request
+  QMap <QString, int>     m_receiver;  // key=Hostname index = id vom videoReceiverObj
+  QNetworkAccessManager *m_qNetworkAccessManager;
+  // QNetworkReply *m_reply;
+  bool m_httpRequestAborted;
+  QTimer m_httpRequestTimer;
+
+  LOGGER_T &m_logger;
+};
+}