Struct-writer

- Fall back to returning bytes when we fail to parse data

Features
- Support python 3.11 - 3.12

Fixes
- Handle enums with negative values
- Support signed integers in bitfields

Change
- Remove the _u from the group union structure name

Fixes
- Generate bit-mask correctly when parsing bit-fields

Fixes
- Handle bytes and str data types when parsing bytes

Features
- Convert from bytes to json using provided definitions
- Assert structures' size matches the total of the member sizes

Change
- Group definitions now require `size` attribute