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/Plugins/AudioVideoManagement/Shared/playback_app.h

@@ -0,0 +1,127 @@
+/**
+  * @RDE_HEADER@
+  * PlaybackApp
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, NLSE, 2018-04-18
+  */
+
+#pragma once
+
+#include <Plugins/AudioVideoManagement/Shared/avmshared_export.h>
+#include <QString>
+#include <QObject>
+#include <memory>
+#include <functional>
+
+class QRect;
+
+namespace AudioVideoManagement
+{
+
+class AvsApp;
+class AvaControl;
+
+// PlaybackApp cannot be a QObject, so we need a wrapper that takes signals, etc.
+class AVMSHARED_EXPORT ObjectWrapper : public QObject
+{
+  Q_OBJECT
+public:
+  ObjectWrapper(QObject *parent) : QObject(parent) {}
+
+signals:
+  void signalVisible();
+  void signalPause();
+  void signalResume();
+};
+
+
+/**
+ * Represents a playback application -- either for video or for audio.
+ * Audio does not require the AVS dialog to be visible and we don't need
+ * a separate application in the Excon-sense for that. Use AppType::AlwaysHidden
+ * for audio.
+ *
+ * The Video PlaybackApp will cover a whole screen as all the other Excon apps do
+ * and will be placed in the same way (see AvsApp).
+ *
+ * PlaybackApp is a resource and can only be used by one client at the same time.
+ *
+ * @author Christian Fröbel
+ */
+class AVMSHARED_EXPORT PlaybackApp
+{
+public:
+
+  enum class AppType
+  {
+    Normal = 1,   //!< Visible AVS-dialog, no auto-hide on release()
+    AutoHide,     //!< Visible AVS-dialog, auto-hide on release()
+    AlwaysHidden  //!< No visible AVS-dialog (for audio playback)
+  };
+
+  /**
+   * Use AppType::AlwaysHidden for Audio.
+   */
+  PlaybackApp(const QString &dialogId, AvaControl *avaControl, AppType);
+  virtual ~PlaybackApp();
+
+  ObjectWrapper *objectWrapper() { return m_objectWrapper; }
+  const QString &dialogId() const { return m_dialogId; }
+
+  /** @return true if someone is using this App. */
+  bool inUse() const { return m_inUse; }
+
+  /**
+   * Resource acquisition.
+   * Don't use directly; use PlaybackAppHandle instead.
+   */
+  ///@{
+  /**
+   * May only be called when inUse() == false.
+   * Will implicitly show the underlying AvsApp.
+   */
+  void acquire();
+  void acquire(const QRect &geometry);
+  void setGeometry(const QRect &geometry);
+  /**
+   * Will implicitly hide the underlying AvsApp when appType == AppType::AutoHide.
+   */
+  void release();
+
+  void hide(bool andClose);
+
+  ///@}
+
+private:
+  const QString             m_dialogId;
+  bool                      m_inUse{false};
+  bool                      m_autoHide;
+  std::unique_ptr<AvsApp>   m_app; //!< only set when appType != AppType::AlwaysHidden
+  ObjectWrapper *m_objectWrapper { nullptr };
+};
+
+
+/**
+ * @author Christian Fröbel
+ */
+class AVMSHARED_EXPORT PlaybackAppHandle
+{
+public:
+  PlaybackAppHandle() = default;
+  explicit PlaybackAppHandle(PlaybackApp *app);
+  PlaybackAppHandle(PlaybackApp *app, const QRect &geometry);
+
+  operator bool() const { return m_app.get() != nullptr; }
+
+  const QString &dialogId() const { return m_app->dialogId(); }
+  void hide(bool andClose = false) { m_app->hide(andClose); }
+  ObjectWrapper *objectWrapper() { return m_app->objectWrapper(); }
+
+private:
+  using Releaser = std::function<void (PlaybackApp *)>;
+  std::unique_ptr<PlaybackApp, Releaser>   m_app;
+};
+
+} // namespace AudioVideoManagement