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/Services/FileManagement/ModuleTests/flm_tests.cpp

@@ -431,10 +431,10 @@ void FlmTests::tryModifyFileContent()
 
     data.id = flc.id;
     data.name = flc.name;
-    if (flc.exerciseId.is_set())
+    if (flc.exerciseId.has_value())
     {
       data.exerciseId = flc.exerciseId.get();
-      if (flc.phaseId.is_set())
+      if (flc.phaseId.has_value())
         data.phaseId = flc.phaseId.get();
     }
     data.fileCategory = flc.fileCategory;