Add property tests comparing hashing with `Ssz` and `SszEx`

[MegaRedHand]

There are multiple that can be done. For an example, see:

https://github.com/lambdaclass/lambda_ethereum_consensus/blob/74663965827d5eeb0e88f40fa134e0899e73394a/test/unit/snappyex_test.exs#L102-L119

As a start, we can add it for basic types, just doing hashing of integers (for bools we can just add both cases as tests), and checking the result is the same.