Check every minute whether authority-discovery key has changed (#8575)

* Check every minute whether authority-discovery key has changed

* Fix test

* Fix comment

* Use HashSet for latest_published_keys

* More fixing

* God I'm tired, sorry

substrate/client/authority-discovery/src/worker/tests.rs

@@ -294,7 +294,7 @@ fn publish_discover_cycle() {
 			Default::default(),
 		);
 
-		worker.publish_ext_addresses().await.unwrap();
+		worker.publish_ext_addresses(false).await.unwrap();
 
 		// Expect authority discovery to put a new record onto the dht.
 		assert_eq!(network.put_value_call.lock().unwrap().len(), 1);