Lookup questionnaire

For items of type reference, the reference can be populated either by picking an existing entity or by creating a new one. In the latter case, this Questionnaire allows specifying the Questionnaire to use in creating the target instance. Typically this will result in a QuestionnaireResponse that can be extracted to produce the desired resource. However, if the target resource for the reference is a QuestionnaireResponse, then the QuestionnaireResponse resulting from the Questionnaire can be referenced directly.