Gloas add process_payload_attestation (#8286)

* process_payload_attestation implemented per eip-7732

* allow duplicates in indexed payload attestation indices

* updates per pr review

beacon_node/store/src/consensus_context.rs

@@ -35,6 +35,8 @@ impl<E: EthSpec> OnDiskConsensusContext<E> {
             proposer_index,
             current_block_root,
             indexed_attestations,
+            indexed_payload_attestations: _,
+            // TODO(EIP-7732): add indexed_payload_attestations to the on-disk format.
         } = ctxt;
         OnDiskConsensusContext {
             slot,