UTF-32
UTF-32 encoding and decoding.
To use the bindings from this module:
(import :std/text/utf32)
string->utf32
(string->utf32 str (endianness 'big) (BOM? #f)) -> u8vector | error
  str        := string
  endianness := endianness symbol; specifies the endianness of the encoding
  BOM?       := boolean; specifies whether to include a BOM or not
Returns a newly allocated u8vector with UTF-32 data from str converted to bytes.
utf32->string
(utf32->string u8v (endianness 'big) (endianness-mandatory? #f)) -> string | error
  u8v                   := u8vector of data to convert
  endianness            := endianness symbol; specifies the endianness of the encoding
  endianness-mandatory? := boolean; if #f then try to read a BOM to determine endianness; if #t then the specified endianness is used.
Returns a newly allocated string with UTF-32 contents from u8v.