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/plugin_settings.cpp

@@ -0,0 +1,93 @@
+/**
+  * @RDE_HEADER@
+  * PluginSettings
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, NLSE, 2018-04-25
+  */
+
+#include "plugin_settings.h"
+#include <nglsettings/nglsettings_settings.h>
+#include <nglsettings/nglsettings_connections.h>
+#include <ngltools/ngltools_filesystem.h>
+#include <QtGlobal>
+#include <QSettings>
+
+
+namespace
+{
+
+const QString &AVA_SECTION()
+{
+  static const QString   key = QStringLiteral("AVS_WORKSTATION");
+  return key;
+}
+
+const QString &VD_SECTION()
+{
+  static const QString   key = QStringLiteral("AVS_WORKSTATION_VD");
+  return key;
+}
+
+//constexpr std::chrono::milliseconds DEFAULT_TIMEOUT(3000);
+constexpr std::chrono::milliseconds DEFAULT_TIMEOUT(10000);
+constexpr std::chrono::milliseconds DEFAULT_TIMEOUT_VD(60000);  // export may take some time
+
+} // anonymous namespace
+
+
+namespace AudioVideoManagement
+{
+
+PluginSettings   *PluginSettings::s_instance = nullptr;
+
+PluginSettings::PluginSettings()
+  : PluginSettings(NGL::findProjectConfigFile())
+{
+  Q_ASSERT(!s_instance);
+  s_instance = this;
+}
+
+PluginSettings::PluginSettings(const QString &pathToConfigFile)
+  : m_settings(new NGL::Settings(pathToConfigFile))
+{
+  NGL::Connections::setIniFile(pathToConfigFile);
+}
+
+PluginSettings::~PluginSettings()
+{
+  s_instance = nullptr;
+}
+
+PluginSettings *PluginSettings::instance()
+{
+  Q_ASSERT(s_instance);
+  return s_instance;
+}
+
+bool PluginSettings::avaKeepAliveEnabled() const
+{
+  static const QString   key = QStringLiteral("%1/KeepAlive").arg(AVA_SECTION());
+  return m_settings->settings()->value(key, true).toBool();
+}
+
+std::chrono::milliseconds PluginSettings::avaTimeout() const
+{
+  static const QString   key = QStringLiteral("%1/Timeout").arg(AVA_SECTION());
+  return std::chrono::milliseconds(m_settings->settings()->value(key, static_cast<unsigned>(DEFAULT_TIMEOUT.count())).toUInt());
+}
+
+bool PluginSettings::vdKeepAliveEnabled() const
+{
+  static const QString   key = QStringLiteral("%1/KeepAlive").arg(VD_SECTION());
+  return m_settings->settings()->value(key, true).toBool();
+}
+
+std::chrono::milliseconds PluginSettings::vdTimeout() const
+{
+  static const QString   key = QStringLiteral("%1/Timeout").arg(VD_SECTION());
+  return std::chrono::milliseconds(m_settings->settings()->value(key, static_cast<unsigned>(DEFAULT_TIMEOUT_VD.count())).toUInt());
+}
+
+} // namespace AudioVideoManagement