multi: break ChannelConstraints into two sub-structures

This commit breaks the ChannelConstraints structure into two
sub-structures that reflect the fundamental differences in how
these parameters are used. On its face it may not seem necessary,
however the distinction introduced here is relevant for how we
will be implementing the Dynamic Commitments proposal.

htlcswitch/test_utils.go

@@ -138,24 +138,28 @@ func createTestChannel(t *testing.T, alicePrivKey, bobPrivKey []byte,
 	csvTimeoutBob := uint32(4)
 	isAliceInitiator := true
 
-	aliceConstraints := &channeldb.ChannelConstraints{
-		DustLimit: btcutil.Amount(200),
+	aliceBounds := channeldb.ChannelStateBounds{
 		MaxPendingAmount: lnwire.NewMSatFromSatoshis(
 			channelCapacity),
 		ChanReserve:      aliceReserve,
 		MinHTLC:          0,
 		MaxAcceptedHtlcs: input.MaxHTLCNumber / 2,
-		CsvDelay:         uint16(csvTimeoutAlice),
+	}
+	aliceCommitParams := channeldb.CommitmentParams{
+		DustLimit: btcutil.Amount(200),
+		CsvDelay:  uint16(csvTimeoutAlice),
 	}
 
-	bobConstraints := &channeldb.ChannelConstraints{
-		DustLimit: btcutil.Amount(800),
+	bobBounds := channeldb.ChannelStateBounds{
 		MaxPendingAmount: lnwire.NewMSatFromSatoshis(
 			channelCapacity),
 		ChanReserve:      bobReserve,
 		MinHTLC:          0,
 		MaxAcceptedHtlcs: input.MaxHTLCNumber / 2,
-		CsvDelay:         uint16(csvTimeoutBob),
+	}
+	bobCommitParams := channeldb.CommitmentParams{
+		DustLimit: btcutil.Amount(800),
+		CsvDelay:  uint16(csvTimeoutBob),
 	}
 
 	var hash [sha256.Size]byte
@@ -172,7 +176,8 @@ func createTestChannel(t *testing.T, alicePrivKey, bobPrivKey []byte,
 	fundingTxIn := wire.NewTxIn(prevOut, nil, nil)
 
 	aliceCfg := channeldb.ChannelConfig{
-		ChannelConstraints: *aliceConstraints,
+		ChannelStateBounds: aliceBounds,
+		CommitmentParams:   aliceCommitParams,
 		MultiSigKey: keychain.KeyDescriptor{
 			PubKey: aliceKeyPub,
 		},
@@ -190,7 +195,8 @@ func createTestChannel(t *testing.T, alicePrivKey, bobPrivKey []byte,
 		},
 	}
 	bobCfg := channeldb.ChannelConfig{
-		ChannelConstraints: *bobConstraints,
+		ChannelStateBounds: bobBounds,
+		CommitmentParams:   bobCommitParams,
 		MultiSigKey: keychain.KeyDescriptor{
 			PubKey: bobKeyPub,
 		},