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/LtsScriptTimeline/track_entry_previewer.cpp

@@ -0,0 +1,86 @@
+#include "track_entry_previewer.h"
+#include "track_entry.h"
+#include "track_entry_painters.h"
+#include "track_content_widget.h"
+
+#include <QPainter>
+#include <QDrag>
+#include <QMimeData>
+#include <QMouseEvent>
+
+
+namespace LtsScriptTimeline
+{
+// only for dnd
+QDataStream &operator<<(QDataStream &ds, const TrackEntry &te);
+QDataStream &operator>>(QDataStream &ds, TrackEntry &te);
+
+TrackEntryPreviewer::TrackEntryPreviewer(QWidget *parent)
+  : QWidget(parent)
+  , m_te(nullptr)
+{
+//  setMinimumSize(50, 50);
+//  setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Maximum);
+  setVisible(false);
+}
+
+
+TrackEntryPreviewer::~TrackEntryPreviewer()
+{}
+
+
+void TrackEntryPreviewer::setTrackEntry(TrackEntry *te)
+{
+  m_te = te;
+
+  if (m_te->isSet) // is already set (no d&d)
+    return;
+
+  connect(m_te, &TrackEntry::destroyed,
+          this, [this]()
+  {
+    m_te = nullptr;
+    emit signalDelete();
+  });
+}
+
+
+void TrackEntryPreviewer::mousePressEvent(QMouseEvent *event)
+{
+  // check if it's a drag + te exists
+  if (!m_te || event->buttons() != Qt::LeftButton)
+    return;
+
+  m_te->isSet = true; // temporary !
+  QByteArray itemData(TrackContentWidget::itemsToData({ m_te }, 0));
+  m_te->isSet = false; // set back, so that THIS te is kept unset
+
+  QMimeData *mimeData = new QMimeData;
+  mimeData->setData(TrackContentWidget::mime, itemData);
+
+  QDrag *drag = new QDrag(this);
+  drag->setDragCursor(QPixmap(), Qt::CopyAction);
+  drag->setMimeData(mimeData);
+
+  emit signalStartDrag();
+
+  if (drag->exec(Qt::CopyAction) == Qt::CopyAction) // exec... grr...
+    emit signalDelete();
+
+  emit signalStopDrag();
+}
+
+
+void TrackEntryPreviewer::paintEvent(QPaintEvent *event)
+{
+  QWidget::paintEvent(event);
+
+  QPainter painter(this);
+
+  if (!m_te)
+    return;
+
+  drawTrackEntry(m_te, painter, rect().adjusted(0, 0, -1, -1), false, isEnabled());
+}
+
+} // namespace LtsScriptTimeline