Enable demographics update and registration handlers process person address and person attributes generically

For a specification of the structure of patient registration payload, see parent ticket (MUZIMA-461).

During processing of the payload, the registration handlers should also be updated to check setting for optional/mandatory patient identifier (See MUZIMA-536) and proceed as follows:

• If the setting is set to true, meaning manual entry of patient identifier is required, fail the registration process if the identifier is missing, otherwise set the identifier as preferred
• If the setting is set to false, meaning manual entry of patient identifier is not expected, check whether the medical record number is present in payload, process it but do not make it preferred. In addition, use id-gen module to generate primary identifier and make it preferred.