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/CodeGen/svc_db_structs.cpp.grantlee

@@ -0,0 +1,95 @@
+/**
+  * @RDE_HEADER@
+  * Template for 'real' structures including insert/update/delete functions for db
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  */
+
+{% autoescape off %}
+// filename: {{ namespace_abbr }}_db_structs.cpp
+#include "{{ namespace_abbr }}_db_structs.h"
+#include "{{ namespace_abbr }}_export.h"
+
+namespace {{ namespace }}
+{
+namespace Database
+{
+QString jsonValueToJsonString(const QJsonValue &value)
+{
+  return value.isNull() ? QStringLiteral("{}") : value.toString();
+}
+
+QString qVariantToJsonString(const QVariant &value)
+{
+  return value.isNull() ? QStringLiteral("{}") : value.toString();
+}
+
+QString fixupEmptyJsonString(const QString &str)
+{
+  return str.isEmpty() ? QStringLiteral("{}") : str;
+}
+
+
+// QPointF
+QJsonValue toJson(const QPointF &element)
+{
+  QJsonObject obj;
+  obj.insert(QStringLiteral("x"), QJsonValue(element.x()));
+  obj.insert(QStringLiteral("y"), QJsonValue(element.y()));
+  return QJsonValue(obj);
+}
+template<>
+QPointF fromJson(const QJsonValue &val)
+{
+  QJsonObject obj = val.toObject();
+  return QPointF(obj.value(QStringLiteral("x")).toDouble(), obj.value(QStringLiteral("y")).toDouble());
+}
+{% if need_point3d %}
+// QPoint3D
+QJsonValue toJson(const LtsUtils::QPoint3D &element)
+{
+  QJsonObject obj;
+  obj.insert(QStringLiteral("x"), QJsonValue(element.x()));
+  obj.insert(QStringLiteral("y"), QJsonValue(element.y()));
+  obj.insert(QStringLiteral("z"), QJsonValue(element.z()));
+  return QJsonValue(obj);
+}
+template<>
+LtsUtils::QPoint3D fromJson(const QJsonValue &val)
+{
+  QJsonObject obj = val.toObject();
+  return LtsUtils::QPoint3D(obj.value(QStringLiteral("x")).toDouble(), obj.value(QStringLiteral("y")).toDouble(), obj.value(QStringLiteral("z")).toDouble());
+}
+{% endif %}
+
+{% for cpp_struct in cpp_structs %}
+//
+// Struct: {{ cpp_struct.name }}
+//
+QJsonObject toJson(const {{ cpp_struct.name }} &element)
+{
+  QJsonObject obj;
+  {% for row in cpp_struct.jsonMember %}
+  {{ row.dbToJsonElement }};
+  {% endfor %}
+  return obj;
+}
+
+template<>
+{{ cpp_struct.name }} fromJson(const QJsonValue &value)
+{
+  const QJsonObject objElement(value.toObject());
+  {{ cpp_struct.name }} element;
+
+  {% for row in cpp_struct.jsonMember %}
+  { {{ row.jsonElementToDb }}; } {% endfor %}
+
+  return element;
+}
+// {{ cpp_struct.name }} end
+{% endfor %}
+
+} // namespace Database
+} // namespace {{ namespace }}
+{% endautoescape %}