Declare transaction hash mismatch

[kkovaacs]

Looks like the computed transaction hashes for Declare v1 transactions are incorrect.

In particular, these lines look suspicious:

    let (calldata, additional_data) = if version.is_zero() {
        (vec![class_hash], vec![nonce])
    } else {
        (Vec::new(), vec![class_hash])
    };

I think it should be exactly the other way around (!version.is_zero()). Adding a test case that tests this should be trivial with this class.