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/frequency_set_handler.h

@@ -0,0 +1,52 @@
+/**
+  * FrequencySetHandler - reads TetraChannel and TvcConfig data from the database and publishes the data to dds,
+  * reacts to TvcConfig related Function topics
+  * $Id: combat_net_radio_handler.h 34915 2017-08-18 07:26:31Z baeuerle_h $
+  * $HeadURL: svn://slssvn/TDS/branches/product/devel/trunk/Lts/Services/AudioVideoManagement/combat_net_radio_handler.h $
+  * $Author: baeuerle_h $
+  * Created by Hannes Baeuerle, SLSE, 2017-07-25
+  */
+#pragma once
+
+#include <avm_db.h>
+#include <avm.hpp>
+#include <logger.h>
+#include <QMap>
+#include <QVector>
+
+namespace AudioVideoManagement
+{
+
+namespace Interface
+{
+  class Dts;
+}
+
+class FrequencySetHandler
+{
+public:
+  explicit FrequencySetHandler(Interface::Dts *dts, DatabaseInterface *db);
+
+  bool init();
+
+  /**
+   * Used by FrequencyPlanningHandler in order to validate the entries of a FrequencyPlan.
+   * Checks whether the given entry is actually part of the FrequencySet.
+   */
+  bool isValid(int32_t setId, int32_t entryId);
+
+  static FrequencyBand getFrequencyBand(const QString &deviceString);
+  
+private: // methods
+  FrequencySet toDdsFrequencySet(const Database::AvmFrequencySet &dbData) const;
+  static FrequencySetDataWithId toDdsFrequencySetDataWithId(const Database::AvmFrequencySetData &dbData);
+  void addFrequencySet(const FrequencySet &frequencySet);
+
+private:
+  Interface::Dts                   *m_dts;
+  DatabaseInterface                *m_db;
+  QMap<int32_t, QVector<int32_t>>   m_frequencySetDatas; // <frequency set id, QVector<frequency set data id> >
+
+  LOGGER_T &m_logger;
+};
+} // namespace AudioVideoManagement