fix(beacon-chain/rpc): correct block root for block events

[Savid]

What type of PR is this?

Bug fix

What does this PR do? Why is it needed?

Fix the beacon node api events block topic to return the correct block root

Other notes for review

Reproduce (should be 0xef43e7ca2477db1424468e2787004330434346114dd201058764246d83a72d07);

curl "http://127.0.0.1:5052/eth/v1/events?topics=block" -H "accept: text/event-stream"

event: block
data: {"slot":"4346322","block":"0xd1f7a5ca3e3293de53ae6a3b7ef0f7df6019d444d4d07f6747e931bccf940366","execution_optimistic":false}

[CLAassistant]

All committers have signed the CLA.

[terencechain]

Thanks!

[rkapka]

You also have to fix TestStreamEvents_BlockEvents like this:

func TestStreamEvents_BlockEvents(t *testing.T) {
	t.Run(BlockTopic, func(t *testing.T) {
		ctx := context.Background()
		srv, ctrl, mockStream := setupServer(ctx, t)
		defer ctrl.Finish()

		blk := util.HydrateSignedBeaconBlock(&eth.SignedBeaconBlock{
			Block: &eth.BeaconBlock{
				Slot: 8,
			},
		})
		bodyRoot, err := blk.Block.Body.HashTreeRoot()
		require.NoError(t, err)
		wantedHeader := util.HydrateBeaconHeader(&eth.BeaconBlockHeader{
			Slot:     8,
			BodyRoot: bodyRoot[:],
		})
		wantedBlockRoot, err := wantedHeader.HashTreeRoot()
		require.NoError(t, err)
		genericResponse, err := anypb.New(&ethpb.EventBlock{
			Slot:                8,
			Block:               wantedBlockRoot[:],
			ExecutionOptimistic: true,
		})
		require.NoError(t, err)
		wantedMessage := &gateway.EventSource{
			Event: BlockTopic,
			Data:  genericResponse,
		}
		wsb, err := blocks.NewSignedBeaconBlock(blk)
		require.NoError(t, err)
		assertFeedSendAndReceive(ctx, &assertFeedArgs{
			t:             t,
			srv:           srv,
			topics:        []string{BlockTopic},
			stream:        mockStream,
			shouldReceive: wantedMessage,
			itemToSend: &feed.Event{
				Type: blockfeed.ReceivedBlock,
				Data: &blockfeed.ReceivedBlockData{
					SignedBlock:  wsb,
					IsOptimistic: true,
				},
			},
			feed: srv.BlockNotifier.BlockFeed(),
		})
	})
}

[rkapka]

Thanks a lot!