Liechtenstein IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "LI",
    ...>    check_digits: "21",
    ...>    bank_code: "08810",
    ...>    branch_code: nil,
    ...>    national_check: nil,
    ...>    account_number: "0002324013AA"
    ...>  }
    ...>  |> IbanEx.Country.LI.to_string()
    "LI 21 08810 0002324013AA"