feat: Incremental aggregation ohbender

[mm-zk]

What ❔

• Added keccak_32 implementation that can run on reduced machine
• In universal verifier - added option to combine 2 proofs with same verification keys together (and their 'public input' will be the keccak of the inputs)
• added flatten-two command in CLI that combines 2 proofs together.
• added CI to test this case.

Why ❔

This allows us to implement 'ohbender' - where we would merge the current proof with the previous one - therefore creating a 'chained' proof, which can be snark-wrapped once.

[github-actions]

Hey there! 👋🏼

We require pull request titles to follow the Conventional Commits specification and it looks like your proposed title needs to be adjusted.
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• feat(zk_evm): Expose more public methods
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Unknown release type "WIP" found in pull request title "WIP: Incremental aggregation". 

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[0xVolosnikov]

lgtm