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/exercise_context.h

@@ -0,0 +1,67 @@
+/**
+  * @RDE_HEADER@
+  * ExerciseContext
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, SLSE, 2017-11-22
+  */
+
+#pragma once
+
+#include "avm_export.h"
+#include <boost/optional.hpp>
+#include <QtGlobal>
+#include <ostream>
+
+class QString;
+class QByteArray;
+
+namespace AudioVideoManagement
+{
+
+/**
+ * Small value class in order to handle the exercise context (string) used in AVS.
+ * Such a context is associated with an exercise ID used by our system.
+ * But AVS also has the notion of a default context named "default"
+ * which has no associated ID on our side.
+ *
+ * @author Christian Fröbel
+ */
+class AVM_COMMON_EXPORT ExerciseContext
+{
+public:
+  explicit ExerciseContext(int exerciseId)
+    : m_exerciseId(exerciseId)
+  {
+    //Q_ASSERT(exerciseId > 0);
+  }
+
+  static ExerciseContext defaultContext() { return ExerciseContext(); }
+
+  static ExerciseContext fromByteArray(const QByteArray &s);
+  static ExerciseContext fromString(const QString &s);
+
+  bool isDefault() const { return !m_exerciseId.is_initialized(); }
+
+  /** May only be called if this is not the "default" context. */
+  int id() const { return *m_exerciseId; }
+
+  QString toString() const;
+  QByteArray toByteArray() const;
+
+  bool operator==(const ExerciseContext &other) const { return m_exerciseId == other.m_exerciseId; }
+  bool operator!=(const ExerciseContext &other) const { return !(*this == other); }
+
+  bool operator<(const ExerciseContext &other) const;
+
+private:
+  /** Create the "default" AVS context. */
+  ExerciseContext() = default;
+
+  boost::optional<int>   m_exerciseId; //!< not set for "default" context
+};
+
+AVM_COMMON_EXPORT std::ostream &operator<<(std::ostream &os, const ExerciseContext &ctx);
+
+} // namespace AudioVideoManagement