Attestation Pool: Reject attestations that are not for the current slot

[Maddiaa0]

Overview

Related to caching the epoch information inside the attestation pool the node is accepting attestations for any slot, we need to filter attestations for the node's current view of the slot.

Validating logic must be added to the gossipsub layer to prevent it forwarding attestations and block proposals that it deems are invalid

Logs from a recent release around the time it crashed

#10327 solves some of the problem, but we also want the p2p layer to have this check integrated into gossip sub, to prevent forwarding of messages which are not for the correct height.