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/Buildings/relay_info_handler.cpp

@@ -0,0 +1,44 @@
+/**
+  * Convert internal gear and charge id to and from tas ids
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Ehrlicher, SLSE, 2016-04-14
+  */
+
+#include "relay_info_handler.h"
+#include "main_handler.h"
+
+namespace Buildings
+{
+RelayInfoHandler::RelayInfoHandler(MainHandler *mainHandler)
+  : QObject()
+  , Interface::Fts::SetRelayInfoRequestHandler(mainHandler->ddsHandler()->fts())
+  , m_mainHandler(mainHandler)
+  , m_logger(getLogger("RelayInfoHandler"))
+{}
+
+RelayInfoHandler::~RelayInfoHandler()
+{}
+
+bool RelayInfoHandler::init()
+{
+  return true;
+}
+
+void RelayInfoHandler::onSetRelayInfoRequest(const rti::core::SampleIdentity &cookie,
+                                             const SetRelayInfoRequest &request)
+{
+  DEBUG_LOG(m_logger) << "onSetRelayInfoRequest " << request;
+  const Core::FunctionReplyObject fro = onSetRelayInfoRequestInternal(request);
+  if (fro.error())
+    WARNING_LOG(m_logger) << fro();
+  m_mainHandler->ddsHandler()->fts()->setRelayInfoReply(cookie, fro);
+}
+
+Core::FunctionReplyObject RelayInfoHandler::onSetRelayInfoRequestInternal(const SetRelayInfoRequest &data)
+{
+  Q_UNUSED(data);
+  return Core::FunctionReplyObject();
+}
+} // namespace Buildings