add blobs cache and fix some block production

beacon_node/http_api/src/lib.rs

@@ -1047,8 +1047,6 @@ pub fn serve<T: BeaconChainTypes>(
              chain: Arc<BeaconChain<T>>,
              network_tx: UnboundedSender<NetworkMessage<T::EthSpec>>,
              log: Logger| async move {
-                // need to have cached the blob sidecar somewhere in the beacon chain
-                // to publish
                 publish_blocks::publish_block(None, block, None, chain, &network_tx, log)
                     .await
                     .map(|()| warp::reply())