multi: update funding workflow to be aware of new tweakless commits

In this commit, we update the funding workflow to be aware of the new
channel type that doesn't tweak the remote party's output within the
non-delay script on their commitment transaction. To do this, we now
allow the caller of `InnitChannelReservation` to signal if they want the
old or new (tweakless) commitment style.

The funding tests are also updated to test both funding variants, as
we'll still need to understand the legacy format for older nodes.

lnwallet/test_utils.go

@@ -88,8 +88,11 @@ var (
 // allocated to each side. Within the channel, Alice is the initiator. The
 // function also returns a "cleanup" function that is meant to be called once
 // the test has been finalized. The clean up function will remote all temporary
-// files created
-func CreateTestChannels(tweaklessCommits bool) (*LightningChannel, *LightningChannel, func(), error) {
+// files created. If tweaklessCommits is true, then the commits within the
+// channels will use the new format, otherwise the legacy format.
+func CreateTestChannels(tweaklessCommits bool) (
+	*LightningChannel, *LightningChannel, func(), error) {
+
 	channelCapacity, err := btcutil.NewAmount(10)
 	if err != nil {
 		return nil, nil, nil, err
@@ -271,7 +274,7 @@ func CreateTestChannels(tweaklessCommits bool) (*LightningChannel, *LightningCha
 		IdentityPub:             aliceKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunder,
+		ChanType:                channeldb.SingleFunderTweakless,
 		IsInitiator:             true,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: bobCommitPoint,
@@ -289,7 +292,7 @@ func CreateTestChannels(tweaklessCommits bool) (*LightningChannel, *LightningCha
 		IdentityPub:             bobKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunder,
+		ChanType:                channeldb.SingleFunderTweakless,
 		IsInitiator:             false,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: aliceCommitPoint,
@@ -301,6 +304,11 @@ func CreateTestChannels(tweaklessCommits bool) (*LightningChannel, *LightningCha
 		Packager:                channeldb.NewChannelPackager(shortChanID),
 	}
 
+	if !tweaklessCommits {
+		aliceChannelState.ChanType = channeldb.SingleFunder
+		bobChannelState.ChanType = channeldb.SingleFunder
+	}
+
 	aliceSigner := &input.MockSigner{Privkeys: aliceKeys}
 	bobSigner := &input.MockSigner{Privkeys: bobKeys}