multi: replace DefaultDustLimit with script-specific DustLimitForSize

This commit updates call-sites to use the proper dust limits for
various script types. This also updates the default dust limit used
in the funding flow to be 354 satoshis instead of 573 satoshis.

lnwallet/test/test_interface.go

@@ -446,7 +446,7 @@ func testDualFundingReservationWorkflow(miner *rpctest.Harness,
 	}
 	aliceChanReservation.SetNumConfsRequired(numReqConfs)
 	channelConstraints := &channeldb.ChannelConstraints{
-		DustLimit:        lnwallet.DefaultDustLimit(),
+		DustLimit:        alice.Cfg.DefaultConstraints.DustLimit,
 		ChanReserve:      fundingAmount / 100,
 		MaxPendingAmount: lnwire.NewMSatFromSatoshis(fundingAmount),
 		MinHTLC:          1,
@@ -896,7 +896,7 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 	}
 	aliceChanReservation.SetNumConfsRequired(numReqConfs)
 	channelConstraints := &channeldb.ChannelConstraints{
-		DustLimit:        lnwallet.DefaultDustLimit(),
+		DustLimit:        alice.Cfg.DefaultConstraints.DustLimit,
 		ChanReserve:      fundingAmt / 100,
 		MaxPendingAmount: lnwire.NewMSatFromSatoshis(fundingAmt),
 		MinHTLC:          1,