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.h

@@ -0,0 +1,55 @@
+/**
+  * @RDE_HEADER@
+  * ViewshedParameter
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  */
+
+#pragma once
+
+// Own
+#include <situation_map_export.h>
+
+#include <MathUtils/math_const.h>
+
+// Qt
+#include <QString>
+#include <QPointF>
+
+class QJsonObject;
+
+//----------------------------------------------------------------------------
+namespace SituationMap
+{
+
+/*!
+ * \brief Define parameter for viewshed.
+ */
+class ViewshedParameter
+{
+public:
+  explicit ViewshedParameter() = default;
+
+  QPointF      viewshedOrigin_latLon;                        // geo coordinates in rad
+  double       innerRadius     =  10.0;                      // inner radius for use with sight fan only
+  double       outerRadius     = 100.0;                      // radius for both sight fan and ESRI viewshed
+  double       observerHeight  = 2.0;                        // observer height for both sight fan and ESRI viewshed
+  double       targetHeight    = 2.0;                        // object or target height for use with sight fan
+  double       startAngle      = 0.0;                        // start angle of sight fan in rad 
+  double       dAngle          = 2.0 / 180.0*MathConst::pi;  // angle of single sight fan beam in rad
+  unsigned int noBeams         = 180;                        // count of sight fan beams 
+  double       alpha           = 1.0;                        // transparency [0..1];
+
+  QString toString() const;
+
+//  static MapWidgetSettings read(const QJsonObject &json);
+//  QJsonObject toJsonObject() const;
+};
+
+
+SITUATIONMAP_EXPORT std::ostream  &operator<< (std::ostream &stream,
+                                               const SituationMap::ViewshedParameter &value);
+
+} // namespace SituationMap
+