lnwire: add btc and node announcement nonces to channel_ready

In preparation for Gossip 1.75, we add new TLV's to the `ChannelReady`
message. Namely: `AnnouncementBitcoinNonce` and `AnnouncementNodeNonce`.
These will be used to exchange nones required for producing the partial
signature to be send in the `AnnouncementSignatures2` message.
The type numbers for these new fields are even because if they are set,
then a peer is expecting its peer to understand gossip 1.75 and the new
fields.

lnwire/lnwire_test.go

@@ -730,18 +730,13 @@ func TestLightningWireProtocol(t *testing.T) {
 		},
 		MsgChannelReady: func(v []reflect.Value, r *rand.Rand) {
 			var c [32]byte
-			if _, err := r.Read(c[:]); err != nil {
-				t.Fatalf("unable to generate chan id: %v", err)
-				return
-			}
+			_, err := r.Read(c[:])
+			require.NoError(t, err)
 
 			pubKey, err := randPubKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
+			require.NoError(t, err)
 
-			req := NewChannelReady(ChannelID(c), pubKey)
+			req := NewChannelReady(c, pubKey)
 
 			if r.Int31()%2 == 0 {
 				scid := NewShortChanIDFromInt(uint64(r.Int63()))
@@ -751,6 +746,24 @@ func TestLightningWireProtocol(t *testing.T) {
 				req.NextLocalNonce = someLocalNonce[NonceRecordTypeT](r)
 			}
 
+			if r.Int31()%2 == 0 {
+				nodeNonce := tlv.ZeroRecordT[
+					tlv.TlvType0, Musig2Nonce,
+				]()
+				nodeNonce.Val = randLocalNonce(r)
+				req.AnnouncementNodeNonce = tlv.SomeRecordT(
+					nodeNonce,
+				)
+
+				btcNonce := tlv.ZeroRecordT[
+					tlv.TlvType2, Musig2Nonce,
+				]()
+				btcNonce.Val = randLocalNonce(r)
+				req.AnnouncementBitcoinNonce = tlv.SomeRecordT(
+					btcNonce,
+				)
+			}
+
 			v[0] = reflect.ValueOf(*req)
 		},
 		MsgShutdown: func(v []reflect.Value, r *rand.Rand) {