Use Gossipsub 1.1 (#1516)

## Issue Addressed

#1172

## Proposed Changes

* updates the libp2p dependency
* small adaptions based on changes in libp2p
* report not just valid messages but also invalid and distinguish between `IGNORE`d messages and `REJECT`ed messages


Co-authored-by: Age Manning <Age@AgeManning.com>

beacon_node/eth2_libp2p/src/config.rs

@@ -99,8 +99,8 @@ impl Default for Config {
         let gs_config = GossipsubConfigBuilder::new()
             .max_transmit_size(GOSSIP_MAX_SIZE)
             .heartbeat_interval(Duration::from_millis(700))
-            .mesh_n(6)
-            .mesh_n_low(5)
+            .mesh_n(8)
+            .mesh_n_low(6)
             .mesh_n_high(12)
             .gossip_lazy(6)
             .fanout_ttl(Duration::from_secs(60))
@@ -111,7 +111,8 @@ impl Default for Config {
             // prevent duplicates for 550 heartbeats(700millis * 550) = 385 secs
             .duplicate_cache_time(Duration::from_secs(385))
             .message_id_fn(gossip_message_id)
-            .build();
+            .build()
+            .expect("valid gossipsub configuration");
 
         // discv5 configuration
         let discv5_config = Discv5ConfigBuilder::new()