autopilot: update AttachmentHeuristics with context

Continue threading context through the autopilot system and remove the
remaining context.TODOs.

autopilot/combinedattach.go

@@ -1,6 +1,7 @@
 package autopilot
 
 import (
+	"context"
 	"fmt"
 
 	"github.com/btcsuite/btcd/btcutil"
@@ -70,9 +71,9 @@ func (c *WeightedCombAttachment) Name() string {
 // is the maximum possible improvement in connectivity.
 //
 // NOTE: This is a part of the AttachmentHeuristic interface.
-func (c *WeightedCombAttachment) NodeScores(g ChannelGraph, chans []LocalChannel,
-	chanSize btcutil.Amount, nodes map[NodeID]struct{}) (
-	map[NodeID]*NodeScore, error) {
+func (c *WeightedCombAttachment) NodeScores(ctx context.Context, g ChannelGraph,
+	chans []LocalChannel, chanSize btcutil.Amount,
+	nodes map[NodeID]struct{}) (map[NodeID]*NodeScore, error) {
 
 	// We now query each heuristic to determine the score they give to the
 	// nodes for the given channel size.
@@ -81,7 +82,7 @@ func (c *WeightedCombAttachment) NodeScores(g ChannelGraph, chans []LocalChannel
 		log.Tracef("Getting scores from sub heuristic %v", h.Name())
 
 		s, err := h.NodeScores(
-			g, chans, chanSize, nodes,
+			ctx, g, chans, chanSize, nodes,
 		)
 		if err != nil {
 			return nil, fmt.Errorf("unable to get sub score: %w",