feat(L1)!: delayed attestation verification

[LHerskind]

Delayed signature verification, sometimes also referred to as optimistic signature verification.

The idea is simple, we already provide proofs once an epoch for the validity of a number of blocks, do the same with attestations, and only

The attestations have a few caveats though;

1. They are providing an early guarantee, not absolute certainty
2. We can easily challenge invalid signatures

Therefore we will keep publishing the signatures but only checking it at the end of the epoch, or earlier if challenged.

Pr for design.
AztecProtocol/engineering-designs#69

Note that as the invalidation can easily be specified to a single entity, slashing can be made fairly instant and without all the fuzz we usually got.

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The "optimistic" part that is haunting the name comes from an early proposal that was to not always challenge, e.g., true optimistic. But we will always challenge at least when the epoch lands, thereby the "delayed" now.

[LHerskind]

A point of interest might be #15362 where a quick and dirty outline was done to get some gas numbers out.

The most important thing also mentioned in the design comments were really to alter the proposer to be drawn from the full set and not the committee such that knowledge of the committee is not necessary.