test(consensus): declare HelloStarknet in the first proposal, assert transactions for reverts

[CHr15F0x]

It turns out that our proposal processing logic did not store successfully declared classes. Which then resulted in deployments failing. This was not covered by the integration tests, which passed happily.

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List of changes:

• the first proposal declares HelloStarknet,
• syncing from consensus now stores the class declaration,
• consensus integration tests check if all the transactions are not reverted, which solves the issue of silent failures (ie. formerly transactions that the test setup required to be executed successfully got reverted which was still a valid outcome of execution as such but not the test as such, and we didn't inspect the receipts while only looking at decided and committed height).

[zvolin]

some first pass, but haven't read through deeply yet 🙈

[kkovaacs]

Looks solid other than the typos / suggested renames.

[t00ts]

🚀