multi: query circuit map inside contractcourt

This commit adds a new config method `QueryIncomingCircuit` that can be
used to query the payment's incoming circuit for giving its outgoing
circuit key.

contractcourt/commit_sweep_resolver_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lntest/mock"
@@ -43,6 +44,11 @@ func newCommitSweepResolverTestContext(t *testing.T,
 			Notifier: notifier,
 			Sweeper:  sweeper,
 			Budget:   *DefaultBudgetConfig(),
+			QueryIncomingCircuit: func(
+				circuit models.CircuitKey) *models.CircuitKey {
+
+				return nil
+			},
 		},
 		PutResolverReport: func(_ kvdb.RwTx,
 			_ *channeldb.ResolverReport) error {