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/AvsCommands/choose_stream.cpp

@@ -0,0 +1,79 @@
+/**
+  * @RDE_HEADER@
+  * ChooseStream
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, SLSE, 2017-06-29
+  */
+
+#include "choose_stream.h"
+#include "iava_comm.h"
+#include "iava_command_done_observer.h"
+
+
+namespace AudioVideoManagement
+{
+
+namespace AvaCommands
+{
+
+ChooseStream::ChooseStream(IAvaComm *comm, IAvaCommandDoneObserver *doneObserver, const QString &dialogId, const QString &streamName)
+  : m_dialogId(dialogId)
+  , m_streamName(streamName)
+  , m_comm(comm)
+  , m_observer(doneObserver)
+{
+  Q_ASSERT(comm);
+  Q_ASSERT(doneObserver);
+}
+
+void ChooseStream::send()
+{
+  connect(m_comm, &IAvaComm::streamInfoReceived, this, &ChooseStream::onStreamInfoReceived);
+  connect(m_comm, &IAvaComm::streamStateReceived, this, &ChooseStream::onStreamStateReceived);
+  connect(m_comm, &IAvaComm::streamModeReceived, this, &ChooseStream::onStreamModeReceived);
+  bool   muted = true;
+  m_comm->chooseStream(m_dialogId, m_streamName, muted);
+}
+
+void ChooseStream::onStreamInfoReceived(const QString &dialogId, const QString &streamName, const AvaStreamInfo &streamInfo)
+{
+  Q_ASSERT(dialogId == m_dialogId);
+  Q_ASSERT(streamName == m_streamName);
+  Q_ASSERT(!m_streamInfo);
+  m_streamInfo = streamInfo;
+}
+
+void ChooseStream::onStreamStateReceived(const QString &dialogId, const QString &streamName, AvaStreamState streamState)
+{
+  Q_ASSERT(dialogId == m_dialogId);
+
+  // There can be multiple StreamStates for every stream that was active.
+  // But all come prior to StreamInfo
+  if (!m_streamInfo)
+    return;
+
+  Q_ASSERT(streamName == m_streamName);
+  Q_ASSERT(!m_streamState);
+  m_streamState = streamState;
+}
+
+void ChooseStream::onStreamModeReceived(const QString &dialogId, const QString &streamName, bool pint, bool autoStop)
+{
+  Q_UNUSED(pint);
+  Q_UNUSED(autoStop);
+  Q_ASSERT(dialogId == m_dialogId);
+  Q_ASSERT(streamName == m_streamName);
+  Q_ASSERT(m_streamInfo);
+  Q_ASSERT(m_streamState);
+  done();
+}
+
+void ChooseStream::done()
+{
+  m_comm->disconnect(this);
+  m_observer->done(this);
+}
+
+}} // namespace AudioVideoManagement::AvaCommands