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/Common/LtsWidgets/lts_background_widget.cpp

@@ -0,0 +1,143 @@
+/**
+  * @RDE_HEADER@
+  * Background Widget that covers a monitor with the project image
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Mike Wille, SLSE, 2016-05-05
+  */
+
+#include "lts_background_widget.h"
+
+#include <QPaintEvent>
+#include <QPainter>
+#include <QDebug>
+
+#ifdef Q_OS_WIN
+#include <QtPlatformHeaders/qwindowswindowfunctions.h>
+#endif
+
+
+namespace LtsWidgets
+{
+
+LtsBackgroundWidget::LtsBackgroundWidget(QWidget *parent)
+  : QDialog(parent)
+  , m_isUltraWide(false)
+{
+  setMouseTracking(true); // register mouse movement
+  setWindowFlags(windowFlags() | Qt::FramelessWindowHint /*| Qt::WindowStaysOnBottomHint*/);
+  setWindowTitle(QStringLiteral("Splash"));
+
+  setBackground();
+}
+
+
+void LtsBackgroundWidget::setBackground()
+{
+  static const auto backgroundFiles =
+  {
+    QStringLiteral(":/project/background.png"),
+    QStringLiteral(":/project/background.jpg"),
+  };
+  static const auto backgroundFilesWide =
+  {
+    QStringLiteral(":/project/background_wide.png"),
+    QStringLiteral(":/project/background_wide.jpg"),
+  };
+
+  m_pixmap = QPixmap();
+  for (const QString &f : m_isUltraWide ? backgroundFilesWide : backgroundFiles)
+  {
+    if (!QFile::exists(f))
+      continue;
+    m_pixmap = QPixmap(f);
+    if (m_pixmap.isNull())
+      continue;
+    break;
+  }
+
+  if (m_pixmap.isNull())
+  {
+    if (m_isUltraWide)
+    {
+      m_isUltraWide = false;
+      setBackground();
+    }
+    else
+    {
+      qWarning() << "BackgroundWidget::c_tor: file missing or is not a valid image ':/project/background.png'";
+    }
+  }
+}
+
+
+void LtsBackgroundWidget::setUltraWide(bool set)
+{
+  if (set == m_isUltraWide) // do not set / unset ultra wide if it's already set to specified state
+    return;
+
+  m_isUltraWide = set;
+  setBackground();
+  update(); // force redraw on next event loop
+}
+
+
+void LtsBackgroundWidget::resizeEvent(QResizeEvent *e)
+{
+  setUltraWide(width() > 3000);
+  QDialog::resizeEvent(e);
+}
+
+
+void LtsBackgroundWidget::paintEvent(QPaintEvent *e)
+{
+  if (!m_pixmap.isNull())
+  {
+    QPainter painter(this);
+    painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
+    painter.drawPixmap(0, 0, width(), height(), m_pixmap); // draw project background on login splash
+  }
+  QDialog::paintEvent(e);
+}
+
+
+bool LtsBackgroundWidget::event(QEvent *e)
+{
+  if (e->type() == QEvent::KeyPress || // respect typing into textfields
+      e->type() == QEvent::MouseButtonPress ||
+      e->type() == QEvent::MouseButtonRelease ||
+      e->type() == QEvent::MouseMove)
+  {
+    //qWarning() << "BGW operator action!";
+    emit signalOperatorAction();
+    e->ignore();
+    return true;
+  }
+
+  return QDialog::event(e);
+}
+
+
+void LtsBackgroundWidget::showFullScreen()
+{
+  //qWarning() << "show fullscreen !";
+#ifdef Q_OS_WIN
+  winId();  // make sure windowHandle() is not a nullptr
+  QWindowsWindowFunctions::setHasBorderInFullScreen(windowHandle(), true);
+#endif
+  QDialog::showFullScreen();
+  raise(); // as this is a widget for the background, it has to be raised, but only once at startup
+}
+
+
+void LtsBackgroundWidget::closeEvent(QCloseEvent *e)
+{
+#ifdef DEVEL
+  deleteLater();
+#else
+  e->ignore();
+#endif
+}
+
+} // namespace LtsWidgets