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/OcBaseDownload/WebSocketInterface/data_manager.h

@@ -0,0 +1,80 @@
+/**
+  * @RDE_HEADER@
+  * The DataManager class is a convenience class for managing structure data
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Philipp Dassow, SLST, 2017-12-05
+  */
+#pragma once
+
+#include "WebSocketInterface/Messages/client_message.h"
+#include "main_handler.h"
+#include "logger.h"
+#include "enums.h"
+
+namespace OcBaseDownload
+{
+
+namespace WebSocketInterface
+{
+
+/**
+ * @brief The DataManager class is a convenience class for managing structure data
+ */
+class DataManager final
+{
+public:
+  /**
+   * @brief DataManager Constructor
+   * @param mainHandler Source for needed handlers
+   */
+  explicit DataManager(MainHandler *mainHandler);
+
+  /**
+   * @brief handleErrorMessage
+   * @param errData
+   */
+  void handleErrorMessage(const Messages::ErrorMessage::ErrorData &errData);
+
+  /**
+   * @brief servicePortsInformation processing new port informations, only called during base DL
+   * @param exerciseInformation
+   */
+  void servicePortsInformation(const QVector<Messages::ServicePortsInformation::ExerciseInformation> &exerciseInformation);
+
+  // handling asm base data
+  template <typename T>
+  void baseData(std::vector<T> &&data)
+  {
+    Q_UNUSED(data)
+    DEBUG_LOG(m_logger) << "Got new base data.";
+    //m_mainHandler->handlerBaseDownload()->handleBaseData(std::move(data));
+  }
+
+  /**
+   * @brief handlePdfListMessage
+   * @param pdfListData a list of PDF document names
+   */
+  void handlePdfListMessage(const Messages::PdfListMessage::PdfListData &pdfListData);
+
+  /**
+   * @brief setCurrentDownload sets the current download
+   * @param currentDownload The new value
+   */
+  void setCurrentDownload(CurrentDownload currentDownload);
+
+  /**
+   * @brief Getter for current download
+   * @return Value of the current download
+   */
+  CurrentDownload currentDownload() const;
+
+private: // attributes
+  MainHandler *m_mainHandler;
+  CurrentDownload                   m_currentDownload;
+  LOGGER_T     m_logger;
+
+}; // class DataManager
+} // namespace WebSocketInterface
+} // namespace OcBaseDownload