Map parent_id to parent_location_id
Map parent_id to parent_location_id

I looked in to changing the form field to parent_location_id instead,
but that felt like a very large change, as custom code deals with that
form too, and I didn't want to couple that to this PR.

dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq