Unarchive questionnaires

Restores the given questionnaires from the archived list. All-or-nothing: every id must belong to the calling company and must not be a template, otherwise nothing is unarchived. Unarchiving is idempotent — unarchiving an already-active questionnaire succeeds and changes nothing. Any status can be unarchived. Each answer request attached to an unarchived questionnaire notifies its answering company.