server: update persistent peer addrs from announcements

In this commit, a subscription is made to topology updates. For any
NodeAnnouncements received for our peristent peers, we store their newly
advertised addresses. If at the time of receiving these new addresses
there are any existing connection requests, these are updated to reflect
the newly advertised addresses.

lntest/itest/lnd_network_test.go

@@ -221,10 +221,10 @@ func testReconnectAfterIPChange(net *lntest.NetworkHarness, t *harnessTest) {
 		[]string{fmt.Sprintf("127.0.0.1:%d", dave.Cfg.P2PPort)},
 	)
 
-	// assert that Dave and Charlie do not reconnect after Dave changes
-	// his P2P address to one not listed in Dave's original advertised list
-	// of addresses. This is a bug that will be fixed in a follow-up commit.
-	assertNotConnected(t, dave, charlie)
+	// assert that Dave and Charlie do reconnect after Dave changes his P2P
+	// address to one not listed in Dave's original advertised list of
+	// addresses.
+	assertConnected(t, dave, charlie)
 }
 
 // assertTimeoutError asserts that a connection timeout error is raised. A