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/Viewer/SituationMap/Map/viewshed_parameter.cpp

@@ -0,0 +1,48 @@
+/**
+  * @RDE_HEADER@
+  * ViewshedParameter
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  */
+
+// Own
+#include "viewshed_parameter.h"
+#include "situation_map_utils.h"
+
+
+//Qt
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+
+#include <sstream>
+
+
+//----------------------------------------------------------------------------
+namespace SituationMap
+{
+
+QString ViewshedParameter::toString() const
+{
+  std::ostringstream stream;
+  stream << " viewshedOrigin_latLon = " << viewshedOrigin_latLon;
+  stream << "; innerRadius = " << innerRadius;
+  stream << "; outerRadius = " << outerRadius;
+  stream << "; observerOffset = " << observerHeight;
+  stream << "; targetOffset = " << targetHeight;
+  stream << "; startArngle = " << startAngle;
+  stream << "; dAngle = " << dAngle;
+  stream << "; noBeams = " << noBeams;
+  stream << "; alpha = " << alpha;
+  return QString::fromLatin1(stream.str().c_str());
+}
+
+std::ostream  &operator<< (std::ostream &stream,
+                           const SituationMap::ViewshedParameter &value)
+{
+  return stream << value.toString();
+}
+
+} // namespace SituationMap
+