Integration with zgp whitelist contract (#4215)

* zgp-transactions checker

* polishing

* rename + refactor

* refuse-service-transactions cl option

* fixed tests compilation

sync/src/tests/helpers.rs

@@ -50,6 +50,7 @@ pub struct TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
 	pub sender: Option<PeerId>,
 	pub to_disconnect: HashSet<PeerId>,
 	pub packets: Vec<TestPacket>,
+	pub peers_info: HashMap<PeerId, String>,
 	overlay: RwLock<HashMap<BlockNumber, Bytes>>,
 }
 
@@ -63,6 +64,7 @@ impl<'p, C> TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
 			to_disconnect: HashSet::new(),
 			overlay: RwLock::new(HashMap::new()),
 			packets: Vec::new(),
+			peers_info: HashMap::new(),
 		}
 	}
 }
@@ -112,6 +114,12 @@ impl<'p, C> SyncIo for TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
 		&*self.chain
 	}
 
+	fn peer_info(&self, peer_id: PeerId) -> String {
+		self.peers_info.get(&peer_id)
+			.cloned()
+			.unwrap_or_else(|| peer_id.to_string())
+	}
+
 	fn snapshot_service(&self) -> &SnapshotService {
 		self.snapshot_service
 	}