Description
Use ISO defaults for JSON/YAML Date/Time serialization, that is
localTime -> DateTimeFormatter.ISO_LOCAL_TIME
localDate -> DateTimeFormatter.ISO_LOCAL_DATE
localDateTime -> DateTimeFormatter.ISO_LOCAL_DATE_TIME
offsetTime -> DateTimeFormatter.ISO_OFFSET_TIME
offsetDateTime -> DateTimeFormatter.ISO_OFFSET_DATE_TIME
zonedDateTime -> DateTimeFormatter.ISO_ZONED_DATE_TIME
(Perhaps backport later to master.)