Get a questionnaire with its sections and questions

The single read behind the questionnaire builder, preview and summary screens: one questionnaire plus its sections and questions, each ordered by sort order. Questions carry their meta blob both nested and flattened onto the question itself, and an attachment question additionally carries a 24-hour signed attachmentFileUrl. The questionnaire must belong to the calling company — another company's questionnaire is indistinguishable from a missing one and answers 404. Archived questionnaires are returned.