useCollectionPlaceForm reseeds the edit form when a different place opens,
fetches a cover photo for a place without one, uploads and removes the custom
cover and saves the edits for both the detail sheet and the phone sheet. The
detail keeps editing the coordinates and keeps a late photo across an update
of the same place; the sheet holds the last place through its exit and drops
a late photo once the place object changes, as before.
Maurice