When PUTing an update to a plot/tree the values are being passed for fields that the user does not have permission to update

[maurizi]

A couple of problems are happening here:

• The server backend does "diffing" to ensure that it doesn't run into permissions issues if it gets "updates" for a non-writeable field, but the new values are the same as the old values. Since we're getting errors, this indicates something is being posted to the server with different values than are stored in the DB, despite changes not being made to that field.
  • On iOS, this was encountered with geom acquiring rounding errors and booleans being silently converted into numbers
• We probably shouldn't include fields in the PUT request at all if the user doesn't have permissions to edit those fields