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/AudioVideoManagement/mounting_point.h

@@ -0,0 +1,60 @@
+/**
+  * @RDE_HEADER@
+  * MountingPoint
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, SLSE, 2017-11-30
+  */
+
+#pragma once
+
+#include "avm_export.h"
+#include <QObject>
+#include <memory>
+
+namespace InfrastructureManagement
+{
+
+class StructureElement;
+
+} // namespace InfrastructureManagement
+
+
+namespace AudioVideoManagement
+{
+
+class Asset;
+
+/**
+ * Part of the data model used by the AssetAssignmentManager.
+ * @author Christian Fröbel
+ */
+class AVM_COMMON_EXPORT MountingPoint : public QObject
+{
+  Q_OBJECT
+public:
+  explicit MountingPoint(const InfrastructureManagement::StructureElement &mountingPoint);
+  ~MountingPoint();
+
+  const InfrastructureManagement::StructureElement &data() const { return *m_data; }
+
+  /** Emits the changed() signal. */
+  void update(const InfrastructureManagement::StructureElement &data);
+
+  /** May only be called when mounted. */
+  Asset *asset() const;
+
+  void mount2(Asset *asset);
+  void unmount2(Asset *asset);
+
+signals:
+  void changed(MountingPoint *mountingPoint);
+
+private:
+  std::unique_ptr<InfrastructureManagement::StructureElement>   m_data;
+  Asset                                                        *m_asset{nullptr}; // null if not mounted
+};
+
+} // namespace AudioVideoManagement
+