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/GeometryModel/geometry_model.cpp

@@ -0,0 +1,38 @@
+/**
+**
+** @RDE_HEADER@
+** GeometryModel to write and read PlanEditor plans.
+** $Id$
+** $HeadURL$
+** $Author$
+**
+** -----------------------------------------------------------------------------------------------
+**
+** Hardware-Environment: Intel-PC
+** Software-Environment: Windows 7, Qt 5.4. ArcGIS 10.2.5
+**
+** Language ........: C++ 11
+**
+** -----------------------------------------------------------------------------------------------
+**
+** Author ...........: Jörg Turla, SPD G, Tel. 3132
+**
+** -----------------------------------------------------------------------------------------------
+**
+** Notes .........:
+**
+**   11.11.2015, JT  : First edition for use with Qt5
+**
+** -----------------------------------------------------------------------------------------------
+*/
+
+#include "geometry_model.h"
+
+namespace SituationMap
+{
+
+  GeometryModel::GeometryModel(QObject *parent) : QObject(parent) {;}
+
+  GeometryModel::GeometryModel(const GeometryModel &) : QObject() {;}
+
+} // namespace SituationMap