umbrello/uml1model/package.{h,cpp}
- Function containedObjects() shall return UMLObjectList by value.
  Reason: In near future we will not be returning a class member.

umbrello/model_utils.cpp
umbrello/models/objectsmodel.cpp
umbrello/umldoc.cpp
umbrello/umllistview.cpp
umbrello/dialogs/pages/packagecontentspage.cpp
- At calls to UMLPackage::containedObjects() receive returned list by
  value.

CCBUG: 73847