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.cpp

@@ -0,0 +1,67 @@
+/**
+  * @RDE_HEADER@
+  * ExerciseContext
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, SLSE, 2017-11-22
+  */
+
+#include "exercise_context.h"
+#include <QString>
+
+namespace
+{
+
+QString EX_PREFIX()       { return QStringLiteral("ex_"); }
+QString DEFAULT_CONTEXT() { return QStringLiteral("Default"); } // case sensitive
+
+} // anonymous namespace
+
+
+namespace AudioVideoManagement
+{
+
+ExerciseContext ExerciseContext::fromByteArray(const QByteArray &s)
+{
+  return fromString(QString::fromLatin1(s));
+}
+
+ExerciseContext ExerciseContext::fromString(const QString &s)
+{
+  if (s == DEFAULT_CONTEXT())
+    return ExerciseContext::defaultContext();
+
+  Q_ASSERT(s.size() > EX_PREFIX().size());
+  Q_ASSERT(s.startsWith(EX_PREFIX()));
+
+  bool   couldConvert = false;
+  int    exerciseId = s.midRef(EX_PREFIX().size()).toInt(&couldConvert);
+  Q_ASSERT(couldConvert);
+  return ExerciseContext(exerciseId);
+}
+
+QString ExerciseContext::toString() const
+{
+  if (isDefault())
+    return DEFAULT_CONTEXT();
+  else
+    return EX_PREFIX() + QString::number(*m_exerciseId);
+}
+
+QByteArray ExerciseContext::toByteArray() const
+{
+  return toString().toLatin1();
+}
+
+bool ExerciseContext::operator<(const ExerciseContext &other) const
+{
+  return m_exerciseId.get_value_or(0) < other.m_exerciseId.get_value_or(0);
+}
+
+std::ostream &operator<<(std::ostream &os, const ExerciseContext &ctx)
+{
+  return os << ctx.toByteArray().constData();
+}
+
+} // namespace AudioVideoManagement