All the types that implement this protocol.
@type iban() :: IbanEx.Iban.t()
@type iban_or_error() :: iban() | {:invalid_checksum, binary()} | {:invalid_format, binary()} | {:invalid_length, binary()} | {:can_not_parse_map, binary()} | {:unsupported_country_code, binary()}
@type t() :: term()
@spec to_iban(t()) :: iban_or_error()