Add unit test coverage for the backup & restore code within the ordering question type.

Tests also need to be added for import & export <_xml,_gift> which may require a core issue or a note on the epic as an acceptance criteria to add tests into question/format/xml & question/format/gift which would be inline with other question types that handle import / export but the work can atleast be done here and maintained somewhere.

Privacy provider coverage would also be nice but since it is a null provider a code coverage ignore may be the best bet here.