feat(fill): blockchain_test to check intermidiate post states in blockchain_test

[winsvega]

shouldn we have

blockchain_test(
        genesis_environment=Environment(),
        pre=pre,
        post=[post1, post2, post3],
        blocks=[Block(txs=[tx_set_pointer_storage, tx_set_sender_storage, tx_reset_code])],
    )

so we validate post state of each block in chain test, not just the final one?

or the post can be part of a block itself and then post in blockchain_test is final post

[danceratopz]

Yup, great idea. We should absolutely add this.