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/Tools/Examples/Plugins/app/main.cpp

@@ -0,0 +1,112 @@
+#include <QApplication>
+#include <QDebug>
+#include <QDir>
+#include <QMainWindow>
+#include <QMap>
+#include <QPluginLoader>
+#include <QVBoxLayout>
+
+#include "../interfaces/child_interface.h"
+#include "../interfaces/parent_interface.h"
+
+int main(int argc, char *argv[])
+{
+  QApplication app(argc, argv);
+
+  QMainWindow mainWindow;
+  QWidget *centralWidget = new QWidget(&mainWindow);
+  QVBoxLayout *mainLayout = new QVBoxLayout(centralWidget);
+  mainWindow.setCentralWidget(centralWidget);
+
+  // Ordnerstruktur auflösen (.../build-.../plugins/)
+  QDir baseDir(QCoreApplication::applicationDirPath());
+  baseDir.cdUp();
+  QDir pluginsDir = baseDir;
+  if (!pluginsDir.cd(QStringLiteral("plugins")))
+  {
+    qCritical() << "Plugins-Ordner nicht gefunden!";
+    return -1;
+  }
+
+  QMap<QString, ParentInterface *> parentPlugins;
+  QList<ChildInterface *> childPlugins;
+
+  // Nur .so-Dateien auflisten (verhindert das Einlesen von cmake_install.cmake)
+  QStringList filters;
+  filters << QStringLiteral("*.so");
+#ifdef Q_OS_WIN
+  filters << QStringLiteral("*.dll");
+#else
+  filters << QStringLiteral("*.so");
+#endif
+
+  // 1. Durchlauf: Plugins laden und katalogisieren
+  for (const QString &fileName : pluginsDir.entryList(filters, QDir::Files))
+  {
+    QPluginLoader loader(pluginsDir.absoluteFilePath(fileName));
+    QObject *pluginInstance = loader.instance();
+
+    if (!pluginInstance)
+    {
+      qDebug() << "Überspringe Datei:" << fileName << loader.errorString();
+      continue;
+    }
+
+    // Ist es ein Parent?
+    auto *parent = qobject_cast<ParentInterface *>(pluginInstance);
+    if (parent)
+    {
+      parentPlugins[parent->pluginName()] = parent;
+      mainLayout->addWidget(parent->widget());
+      qDebug() << "Eltern-Plugin registriert:" << parent->pluginName();
+      continue;
+    }
+
+    // Ist es ein Child?
+    auto *child = qobject_cast<ChildInterface *>(pluginInstance);
+    if (child)
+    {
+      childPlugins.append(child);
+      qDebug() << "Kind-Plugin zwischengespeichert:" << child->childName();
+    }
+  }
+
+  // 2. Durchlauf: Zuordnen, Daten übergeben und Signale verbinden
+  for (ChildInterface *child : childPlugins)
+  {
+    QString target = child->targetParentName();
+
+    if (parentPlugins.contains(target))
+    {
+      ParentInterface *parent = parentPlugins[target];
+
+      // A. Widget zuweisen
+      parent->addChildWidget(child->widget());
+      qDebug() << "Kind" << child->childName() << "wurde" << target << "zugeordnet.";
+
+      // B. Initiale Parameterübergabe
+      child->setParentData(QStringLiteral("Konfig-Paket via %1").arg(parent->pluginName()));
+
+      // C. Dynamische Signal-Slot Live-Verbindung (Absturzsicher via Pointer-Check)
+      QObject *parentObj = parent->qobjectInstance();
+      QObject *childObj = dynamic_cast<QObject *>(child);
+
+      if (parentObj && childObj)
+      {
+        bool connected = QObject::connect(parentObj, SIGNAL(dataChangedLive(QString)), childObj, SLOT(updateLiveData(QString)));
+        if (connected)
+          qDebug() << "Live-Signal verbunden für:" << child->childName();
+        else
+          qWarning() << "Verbindung fehlgeschlagen für:" << child->childName();
+      }
+      else
+        qWarning() << "Fehler beim Casten des Plugins" << child->childName() << "zu QObject!";
+    }
+    else
+      qDebug() << "Warnung: Kein Parent gefunden für" << child->childName();
+  }
+
+  mainWindow.resize(500, 450);
+  mainWindow.show();
+  return app.exec();
+}