routing+htlcswitch+discovery+peer+netann: optimize debug logging with lazy evaluation

In this commit, we update the network and routing layer components to use
lnutils.SpewLogClosure for debug logging.

routing/payment_lifecycle.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/btcsuite/btcd/btcec/v2"
-	"github.com/davecgh/go-spew/spew"
 	sphinx "github.com/lightningnetwork/lightning-onion"
 	"github.com/lightningnetwork/lnd/fn/v2"
 	"github.com/lightningnetwork/lnd/graph/db/models"
@@ -301,7 +300,7 @@ lifecycle:
 			continue lifecycle
 		}
 
-		log.Tracef("Found route: %s", spew.Sdump(rt.Hops))
+		log.Tracef("Found route: %s", lnutils.SpewLogClosure(rt.Hops))
 
 		// We found a route to try, create a new HTLC attempt to try.
 		attempt, err := p.registerAttempt(rt, ps.RemainingAmt)
@@ -767,7 +766,7 @@ func (p *paymentLifecycle) amendFirstHopData(rt *route.Route) error {
 
 			log.Debugf("Aux traffic shaper returned custom "+
 				"records %v and amount %d msat for HTLC",
-				spew.Sdump(newRecords), newAmt)
+				lnutils.SpewLogClosure(newRecords), newAmt)
 
 			return fn.Ok(extraDataRequest{
 				customRecords: fn.Some(newRecords),

routing/router.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcutil"
-	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/amp"
 	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/fn/v2"
@@ -958,7 +957,8 @@ func spewPayment(payment *LightningPayment) lnutils.LogClosure {
 		}
 		p := *payment
 		p.RouteHints = routeHints
-		return spew.Sdump(p)
+
+		return lnutils.SpewLogClosure(p)()
 	})
 }