Ukrainian IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "UA",
    ...>    check_digits: "21",
    ...>    bank_code: "322313",
    ...>    branch_code: nil,
    ...>    national_check: nil,
    ...>    account_number: "0000026007233566001"
    ...>  }
    ...>  |> IbanEx.Country.UA.to_string()
    "UA 21 322313 0000026007233566001"