Expand api wrapper constant handling

This fix means that any field for which 'getoptions' work will do api wrapper layer conversion of label to id

e.g financial_type_id = 'Donation' will be converted to financial_type_id=1 at the api wrapper layer

Note that the application of CRM_Utils_Rule is still not being applied but fields where options are defined & not met are not being accepted. No test regression from this.