nints / bools compile errors

[rooooooooob]

As of the fixes in #53 babbage.cddl now runs through codegen, but there are various compile errors still existing relating to the above types:

1. bool::deserialize() error (likely easy to fix - might only be with preserve-encodings)
2. 5577 | ... Ok(x, enc) => (x as i64, Some(enc)),
   | ^ ^^^ expected 1 field, found 2
   and
   5304 | ... serializer.write_negative_integer_sz(*value as i128, fit_sz(*value as i128, key_9_value_value_encoding, force_canonical))?;
   | ^^^^^^^^^^^^^^ expected u64, found i128
   both look like it's an issue with negative ints with preserve-encodings=true