Binpi

Fixes:
- SimpleSerializableType as `size` argument for Lists didn't use endinianess

Features:
- Now you can pass SimpleSerializableType as `size` parameter to `binpi.List`, binpi will then read the size from the binary stream and then read the correct amount of data (`{size}|element1|element2|element3`)

- Add Enum parsing
- Move endianness from types to the serialize & deserialize functions (LEInt -> just Int)

Features:
- Use fields of subclasses