Optimize Gossip Validations with Blob Inclusion Header Signature

[terencechain]

With the introduction of blob inclusion proof and new format of blob sidecar, the process of gossip validations across blob sidecar(s) and beacon block has become more efficient. Specifically, we now only have to verify a single signature. This issue aims to track the work related to these optimizations.

[kasey]

groundwork for this was laid here #13245
and I believe it will be wired into gossip here #13294

Note that this will cache signature verification amongst the blobs, but to also share the cache with blocks, we need to add a verification.BlockVerifier and use that in place of block gossip validation code.

[kasey]

In gossip, we cache signature verification for blobs amongst the BlobSidecars, but not with the block verification. I think this state is OK for now and we can mark this for later improvement.

In batch sync, we trust the block batch processor to perform signature checks before calling the DA check and do a cheap comparison of the signature bytes.

So I think this is resolved for now and we can make a lower priority ticket for sharing the blob sig cache with blocks.