message: fix(decoders) Remove the `unsafe` block in the `string` parser.
  Instead of using `str::from_utf8_unchecked`, this patch updates the
  code to use `str::from_utf8` and handles the error appropriately.
diff: @@ -91,9 +91,11 @@ fn string<'input, E: ParseError<&'input [u8]>>(
  return Err(Err::Error(make_error(input, ErrorKind::Eof)));
  }
  - Ok((&input[length..], unsafe {
  - str::from_utf8_unchecked(&input[..length])
  - }))
  + Ok((
  + &input[length..],
  + str::from_utf8(&input[..length])
  + .map_err(|_| Err::Error(make_error(input, ErrorKind::ParseTo)))?,
  + ))
  }
  /// Parse a list, with a item parser.
  