Add roundtrip and more tests to ParseISO8601DateTime and FormatISO8601DateTime
Add roundtrip and more tests to ParseISO8601DateTime and FormatISO8601DateTime


Former-commit-id: 658b876b7d74019ef7b41fbfacc38303d7f8edf6
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin