Ban peer race condition (#4140)

It is possible that when we go to ban a peer, there is already an unbanned message in the queue. It could lead to the case that we ban and immediately unban a peer leaving us in a state where a should-be banned peer is unbanned. 

If this banned peer connects to us in this faulty state, we currently do not attempt to re-ban it. This PR does correct this also, so if we do see this error, it will now self-correct (although we shouldn't see the error in the first place). 

I have also incremented the severity of not supporting protocols as I see peers ultimately get banned in a few steps and it seems to make sense to just ban them outright, rather than have them linger.

beacon_node/lighthouse_network/src/service/mod.rs

@@ -1119,7 +1119,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
                 debug!(self.log, "Peer does not support gossipsub"; "peer_id" => %peer_id);
                 self.peer_manager_mut().report_peer(
                     &peer_id,
-                    PeerAction::LowToleranceError,
+                    PeerAction::Fatal,
                     ReportSource::Gossipsub,
                     Some(GoodbyeReason::Unknown),
                     "does_not_support_gossipsub",