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/Services/MeteoDataManagement/main_handler.h

@@ -0,0 +1,55 @@
+/**
+  * MainHandler for MeteoDataManagement
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by hjl, SLSE, 2016-09-21
+  */
+
+#pragma once
+
+#include "handler_infrastructure_data.h"
+#include "handler_meteo_data_units.h"
+#include "handler_static_meteo_data.h"
+
+#include "dds_handler.h"
+#include "mdm_db.h"
+#include "logger.h"
+
+namespace GuezNasat
+{
+class Initialization;
+}
+
+namespace NGLDB
+{
+template <typename DB> class DbServiceHandler;
+}
+
+namespace MeteoDataManagement
+{
+using DbHandler = NGLDB::DbServiceHandler<DatabaseInterface>;
+class MainHandler
+{
+public:
+  explicit MainHandler();
+  ~MainHandler();
+
+  bool init(int domainId);
+
+  std::shared_ptr<DdsHandler> dds() const { return m_ddsHandler; }
+  std::shared_ptr<DatabaseInterface> db() const;
+  std::shared_ptr<HandlerInfrastructureData> ism() const { return m_handlerInfrastructureData; }
+private:
+  QString initInternal(int domainId);
+private: // attributes
+  std::shared_ptr<DdsHandler>                m_ddsHandler;                ///< Pointer to DDS handler
+  std::shared_ptr<DbHandler>                 m_dbHandler;                 ///< Pointer to DB handler
+  std::shared_ptr<HandlerMeteoDataUnits>     m_handlerMeteoDataUnits;     ///< Pointer to meteo data units handler
+  std::shared_ptr<HandlerInfrastructureData> m_handlerInfrastructureData; ///< Pointer to infrastructure data handler
+  std::shared_ptr<HandlerStaticMeteoData>    m_handlerStaticMeteoData;    ///< Pointer to static meteo data handler
+  GuezNasat::Initialization                 *m_gnaService;
+
+  NGL::INGLLogger                            &m_logger;                   ///< Interface to the Logging-Facility
+};
+} // namespace MeteoDataManagement