routing: track unifiedPolicyEdge

Preparation so that we can have the inbound fee available
in addition to the outgoing policy.

routing/heap.go

@@ -3,7 +3,6 @@ package routing
 import (
 	"container/heap"
 
-	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing/route"
 )
@@ -39,7 +38,7 @@ type nodeWithDist struct {
 	weight int64
 
 	// nextHop is the edge this route comes from.
-	nextHop *models.CachedEdgePolicy
+	nextHop *unifiedEdge
 
 	// routingInfoSize is the total size requirement for the payloads field
 	// in the onion packet from this hop towards the final destination.