us-ph-postpartum-status.observation.value[x] binding is to time periods, not a "status"

We have confirmed that the public health requirement for Postpartum Status is a simple Yes/No (i.e. a status). It would be used to identify important follow up on a neonate if the mother had a condition and PH didn’t know the mother had been pregnant. PH does not need to know the duration. This element is a flag for some conditions to initiate additional investigation of the baby. We will remove the binding to the value set and bind to a simple yes/no/unknown value set. We will also update the description including defining the meanings of yes and no. Profile name will be updated to be "Is Postpartum"