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/Plugins/ProjectionWorkstation/Gui/WebSocket/pws_web_socket_client.cpp

@@ -0,0 +1,33 @@
+#include "pws_web_socket_client.h"
+#include <LtsProjectionWorkstation/WebSocket/message_factory.h>
+
+namespace ProjectionWorkstation
+{
+
+WebSocketClient::WebSocketClient(LtsProjectionWorkstation::MessageFactory *messageFactory, QObject *parent)
+  : LtsWebSocket::ClientConnection(nullptr, parent)
+  , m_messageFactory(messageFactory)
+{
+  connect(this, &LtsWebSocket::ClientConnection::newTextMessage, this, &WebSocketClient::onNewTextMessage);
+  init();
+}
+
+void WebSocketClient::onNewTextMessage(LtsWebSocket::ClientConnection *client, const QString &message)
+{
+  LtsWebSocket::AbstractClientMessage *clientMessage = nullptr;
+  auto result = m_messageFactory->parseMessage(message);
+  if (QJsonParseError::NoError == result.error)
+    clientMessage = m_messageFactory->createMessage(client, message);
+  else
+  {
+//    WARNING_LOG(m_logger) << "Could not parse incoming message: '" << message << "', error: " << result.errorString();
+    clientMessage = new LtsWebSocket::InvalidMessage(client, QString(), QStringLiteral("Got message which is not JSON conform"));
+  }
+
+  if (clientMessage)
+    clientMessage->process();
+
+  delete clientMessage;
+}
+
+} // ProjectionWorkstation

qt5-before/dlbo/Lts/Plugins/ProjectionWorkstation/Gui/WebSocket/pws_web_socket_client.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <LtsWebSocket/client_connection.h>
+
+namespace LtsProjectionWorkstation { class MessageFactory; }
+
+namespace ProjectionWorkstation
+{
+
+class WebSocketClient : public LtsWebSocket::ClientConnection
+{
+  Q_OBJECT
+public:
+  explicit WebSocketClient(LtsProjectionWorkstation::MessageFactory *messageFactory, QObject *parent = nullptr);
+
+public slots:
+  void onNewTextMessage(ClientConnection *client, const QString &message);
+
+private:
+  LtsProjectionWorkstation::MessageFactory *m_messageFactory;
+};
+
+} // ProjectionWorstation