interop: Proposal migration

[Inphi]

Now that OPCM can handle migrating pre-interop chains to a single DGF and shared ETHLockBox, we still need to lock down this migration for fault proofs.

We've got to make sure all Super Dispute Games created after interop are anchored by a trusted chain state. @ajsutton has a cool PoC that does this migration by anchoring the initial super root state on finalized output roots. This is a clean and trustless procedure.

We need to take this PoC and turn it into something production-ready that works with superchain upgrades. I'm thinking OPCM would handle migrating the proposals and updating the ASR, but I'm not 100% on that. Let's look into our options here.