multi: set the InboundFee on ChannelEdgePolicy

In this commit, we make sure to set the new field wherever appropriate.
This will be any place where the ChannelEdgePolicy is constructed other
than its disk deserialisation.

graph/notifications_test.go

@@ -121,6 +121,7 @@ func randEdgePolicy(chanID *lnwire.ShortChannelID,
 		FeeBaseMSat:               lnwire.MilliSatoshi(prand.Int31()),
 		FeeProportionalMillionths: lnwire.MilliSatoshi(prand.Int31()),
 		ToNode:                    node.PubKeyBytes,
+		InboundFee:                fn.Some(inboundFee),
 		ExtraOpaqueData:           extraOpaqueData,
 	}, nil
 }