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/DifferentialGPS/mainthread.cpp

@@ -0,0 +1,127 @@
+/**
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  */
+
+#include "mainthread.h"
+
+#include "tetra_if_impl.h"
+#include "trimble_if.h"
+
+#include <QMutexLocker>
+#include <QTimer>
+#include <DDS/Core/pacemaker.h>
+
+namespace DifferentialGPS
+{
+MainThread::MainThread(QObject *parent)
+  : QObject(parent)
+  , m_ddsHandler(nullptr)
+  , m_dgpsTimer(new QTimer(this))
+  , m_tetraIfNum(0)
+  , m_trimbleIfNum(0)
+  , m_logger(getLogger("MainThread"))
+  , m_broadcastTime(QTime::currentTime())
+  , m_broadcastCycle_ms(10000)
+{
+  m_tetraIF[0] = new TetraImpl;
+  m_tetraIF[1] = new TetraImpl;
+
+  m_trimbleIF[0] = new TrimbleIF;
+  m_trimbleIF[1] = new TrimbleIF;
+
+  connect(this, &MainThread::newDataAvailable,
+          m_tetraIF[m_tetraIfNum], &TetraImpl::onNewDataAvailable,
+          Qt::QueuedConnection);
+
+}
+
+MainThread::~MainThread()
+{
+  m_ddsHandler = nullptr;
+
+  m_tetraIF[0]->quit();
+  m_tetraIF[1]->quit();
+  m_trimbleIF[0]->quit();
+  m_trimbleIF[1]->quit();
+
+  m_tetraIF[0]->wait();
+  m_tetraIF[1]->wait();
+  m_trimbleIF[0]->wait();
+  m_trimbleIF[1]->wait();
+
+  delete m_tetraIF[0];
+  delete m_tetraIF[1];
+  delete m_trimbleIF[0];
+  delete m_trimbleIF[1];
+}
+
+
+bool MainThread::init(int domainId)
+{
+  m_ddsHandler.reset(new DdsHandler(domainId));
+  if (!m_ddsHandler->init())
+  {
+    ERROR_LOG(m_logger) << "Initialisation DdsHandler failed.";
+    m_ddsHandler->pacemaker()->setNewState(Core::RunningState::StartingError);
+    return false;
+  }
+
+  m_trimbleIF[0]->startThread(0, this);
+  m_trimbleIF[1]->startThread(1, this);
+
+  m_tetraIF[m_tetraIfNum]->startThread(m_tetraIfNum, this);
+
+  m_ddsHandler->pacemaker()->setNewState(Core::RunningState::Running);
+  return true;
+}
+
+void MainThread::addNewData(const QByteArray &ba, int trimbleIfNum)
+{
+  const int cycle_ms = m_broadcastCycle_ms + (m_broadcastCycle_ms / 5); // Zykluszeit + 20%
+  QTime currentTime  = QTime::currentTime();
+
+  bool overtake = (trimbleIfNum == m_trimbleIfNum);
+  if (!overtake)
+  {
+    if (m_broadcastTime.msecsTo(currentTime) > cycle_ms)
+    {
+      overtake        = true;
+      m_trimbleIfNum  = trimbleIfNum; // Lese ab jetzt bevorzugt von diesem IF
+    }
+  }
+
+  if (overtake)
+  {
+    QMutexLocker l(&m_mutex);
+    m_dgpsData = ba;
+    if (m_tetraIF[m_tetraIfNum]->isRunning())
+      emit newDataAvailable();
+    else
+    {
+      disconnect(this, &MainThread::newDataAvailable,
+                 m_tetraIF[m_tetraIfNum], &TetraImpl::onNewDataAvailable);
+      m_tetraIfNum = (m_tetraIfNum + 1) % 2;
+      connect(this, &MainThread::newDataAvailable,
+              m_tetraIF[m_tetraIfNum], &TetraImpl::onNewDataAvailable,
+              Qt::QueuedConnection);
+
+      m_tetraIF[m_tetraIfNum]->startThread(m_tetraIfNum, this);
+    }
+
+    m_broadcastTime = currentTime; // Die Broadcast-Zeit merken
+  }
+
+}
+
+bool MainThread::getNewData(QByteArray &ba)
+{
+  QMutexLocker l(&m_mutex);
+  if (!m_dgpsData.size())
+    return false;
+  ba = m_dgpsData;
+
+  return true;
+}
+} // namespace DifferentialGPS