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/TrainingAreaBase/exm_handler.cpp

@@ -37,7 +37,7 @@ ExerciseManagement::Exercise ExmHandler::exercise(int exerciseId)
 
 void ExmHandler::onExerciseChanged(const ExerciseManagement::Exercise &data, DataModification modType)
 {
-  if (!data.radioGroupId.is_set() || data.radioGroupId.get() == 0)
+  if (!data.radioGroupId.has_value() || data.radioGroupId.get() == 0)
     modType = DataModification::eRemoved;
 
   bool bExercise2RadioGroupChanged = false;