Complete Qt6 migration: full clean build green across groups G1-G12 incl. runtime plugin set

new_docker_build.sh gains Group 12 (212 GUI/Data plugins); fixes LtsUtilsGuiDds visibility (LTO-stripped exports), LtsProjectionWorkstation unity name shadow, 6 unity-off dirs (dup file-scope statics, ddsftc INTERFACE sources) and reconfigures BUILD_FILTERMANAGEMENT/BUILD_PLUGINS_SERVICEMONITOR=ON

qt6-after/qt6-migrated-legatus/Lts/Proxies/HighLevelArchitecture/Apache/aes_handler.cpp

@@ -62,7 +62,7 @@ void AesHandler::onAirSupportImpact(AirSupportImpactModifyRequest asi, int equip
 {
   asi.participantId(m_dtcPpm->participantIdByEquipmentNumber(equipmentNumber));
 
-  if (!asi.externalId().is_set())
+  if (!asi.externalId().has_value())
     return;
 
   m_requestHelper->startSingleRequest([this, asi]()