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/Proxies/HighLevelArchitecture/Common/identifierstruct.h

@@ -0,0 +1,69 @@
+/**
+  * Helper Class for handling Entity IdentifierStructs
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Malte Diers, NLE, 2019-07-11
+  */
+
+#pragma once
+
+#include <QString>
+#include <Common/hlacommon_export.h>
+
+namespace rpr2
+{
+class EntityIdentifierStruct;
+}
+
+namespace HighLevelArchitecture
+{
+
+class HLACOMMON_EXPORT IdentifierStruct
+{
+public:
+  IdentifierStruct() = default;
+  explicit IdentifierStruct(quint16 equipmentNo)
+    : m_siteId(ownSiteId())
+    , m_applicationId(ownApplicationId())
+    , m_entityNumber(equipmentNo)
+  {}
+
+  explicit IdentifierStruct(const rpr2::EntityIdentifierStruct &eis);
+
+  static IdentifierStruct fromInt64(qint64 value);
+
+  quint16 siteId() const { return m_siteId; }
+  void setSiteId(quint16 siteId) { m_siteId = siteId; }
+
+  quint16 applicationId() const { return m_applicationId; }
+  void setApplicationId(quint16 applicationId) { m_applicationId = applicationId; }
+
+  quint16 entityNumber() const { return m_entityNumber; }
+  void setEntityNumber(quint16 entityNumber) { m_entityNumber = entityNumber; }
+
+  static quint16 ownSiteId();
+  static void setOwnSiteId(quint16 siteId) { s_ownSiteId = siteId; }
+
+  rpr2::EntityIdentifierStruct toEIS() const;
+  QString toString() const;
+  qint64 toInt64() const;
+
+  bool isOwnElement() const { return siteId() == ownSiteId() && applicationId() == ownApplicationId(); }
+  void makeOwn();
+
+  bool isNull() const { return (m_siteId == 0 && m_applicationId == 0 && m_entityNumber == 0); }
+
+  static quint16 getNextId() { return s_nextId++; }
+
+private:
+  quint16 m_siteId = 0;
+  quint16 m_applicationId = 0;
+  quint16 m_entityNumber = 0;
+
+  static quint16 ownApplicationId();
+  static quint16 s_nextId;
+  static quint16 s_ownSiteId;
+};
+
+}