Delete temporary observations if the associated form is moved back to draft

Currently (as of version 2.4.0), mUzima allows creating temporary Obs extracted from encounter forms (see MUZIMA-777). The app also allows moving completed forms back to draft for further editing. However, the app does not remove the temporary Obs associated with form data when the form is moved back to draft. This leads to duplication of temporary observations when the form is moved to draft and saved as complete thereafter.

A remedy to this issue is to ensure temporary Obs associated with a form are removed whenever the form is moved back to draft.