AVM Testnet: Integrate base rollup with a fake avm recursive verifier

[jeanmon]

The avm circuit will go under strong changes which make it unsuitable to be verified during beginning of testnet phase. Each constraint modifications imply a different avm recursive verifier.
For this reason, it was agreed to create a dummy/fake recursive verifier which has a similar number of ultra_honk gates as the expected final recursive verifier (ca. 3000 avm columns).