Switzerland IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "CH",
    ...>    check_digits: "93",
    ...>    bank_code: "00762",
    ...>    branch_code: nil,
    ...>    national_check: nil,
    ...>    account_number: "011623852957"
    ...>  }
    ...>  |> IbanEx.Country.CH.to_string()
    "CH 93 00762 011623852957"