fix: batch validation for electra attestations

[twoeths]

Motivation

In order to do batch validation, we extract AttestationData base64 from its serialized data but it's not enough for electra. We need to also extract committeeBits instead

This issue would lead to invalid aggregated attestations when there are more than committee indices per slot

Description

• Based on fork, extract either AttestationData (for phase0) or AttestationData + CommitteeBits (electra)
• This is used for SeenAttestationDatas cache and IndexedGossipQueue
• After batch gossip validation, we should have committeeIndex so that we don't extract again in attestation pool
• Also fixed the bug we saw yesterday regarding undefined committeeBits

Need some more testing for this PR

[twoeths]

miss committeeBits yesterday which caused the serialization issue @nflaig

[wemeetagain]

is there a way to make this more typesafe?
I'll make an issue for later, but there are some patterns in our code that lead to this kind of bug (that we should clean up later).

[twoeths]

yeah need to review carefully and address when we merge electra to unstable I guess @wemeetagain

[twoeths]

was able to reproduce the issue if I use "minimal", 64 validators x 4 clients, which make it 256 validators. With 8 slots per epoch we have 32 validators per slot, with TARGET_COMMITTEE_SIZE = 4 for minimal we have 32 : 4 = 8 committees per slot

got this error

[cl-1-lodestar-nethermind] May-16 07:49:32.307[api]             error: Error on publishAggregateAndProofs [0] slot=8, index=0, code=ATTESTATION_ERROR_INVALID_SIGNATURE
[cl-1-lodestar-nethermind] Error: ATTESTATION_ERROR_INVALID_SIGNATURE
[cl-1-lodestar-nethermind]     at validateAggregateAndProof (file:///usr/app/packages/beacon-node/src/chain/validation/aggregateAndProof.ts:230:11)
[cl-1-lodestar-nethermind]     at validateGossipFnRetryUnknownRoot (file:///usr/app/packages/beacon-node/src/network/processor/gossipHandlers.ts:749:14)
[cl-1-lodestar-nethermind]     at file:///usr/app/packages/beacon-node/src/api/impl/validator/index.ts:1106:76
[cl-1-lodestar-nethermind]     at async Promise.all (index 0)
[cl-1-lodestar-nethermind]     at Object.publishAggregateAndProofs (file:///usr/app/packages/beacon-node/src/api/impl/validator/index.ts:1096:7)
[cl-1-lodestar-nethermind]     at Object.handler (file:///usr/app/packages/api/src/utils/server/genericJsonServer.ts:45:23)

[twoeths]

ATTESTATION_ERROR_INVALID_SIGNATURE was gone as confirm in @ensi321 environment