Metadata fields managed internally by the library: the guid, timestamps and
local sync state. These are automatically set on add_address and updated on
operations like touch and update_address. Not included in
UpdatableAddressFields; use add_address_with_meta when importing records
that already have metadata.
A bulk insert result entry, returned per input record by
add_many_addresses_with_meta so that one record failing does not abort the
batch. Note that although the success case is much larger than the error
case, this is negligible in real life, as we expect a very small
success/error ratio.