multi: move failed attempt cfg option to the router subsytem

Previously we had db and application logic mixed on the db level.
We now move the config option KeepFailedPaymentAttempts to the
ChannelRouter level and move it out of the db level.

payments/db/kv_store.go

@@ -127,10 +127,6 @@ type KVStore struct {
 
 	// db is the underlying database implementation.
 	db kvdb.Backend
-
-	// keepFailedPaymentAttempts is a flag that indicates whether we should
-	// keep failed payment attempts in the database.
-	keepFailedPaymentAttempts bool
 }
 
 // A compile-time constraint to ensure KVStore implements DB.
@@ -152,8 +148,7 @@ func NewKVStore(db kvdb.Backend,
 	}
 
 	return &KVStore{
-		db:                        db,
-		keepFailedPaymentAttempts: opts.KeepFailedPaymentAttempts,
+		db: db,
 	}, nil
 }
 
@@ -288,19 +283,14 @@ func (p *KVStore) InitPayment(_ context.Context, paymentHash lntypes.Hash,
 	return updateErr
 }
 
-// DeleteFailedAttempts deletes all failed htlcs for a payment if configured
-// by the KVStore db.
+// DeleteFailedAttempts deletes all failed htlcs for a payment.
 func (p *KVStore) DeleteFailedAttempts(ctx context.Context,
 	hash lntypes.Hash) error {
 
-	// TODO(ziggie): Refactor to not mix application logic with database
-	// logic. This decision should be made in the application layer.
-	if !p.keepFailedPaymentAttempts {
-		const failedHtlcsOnly = true
-		err := p.DeletePayment(ctx, hash, failedHtlcsOnly)
-		if err != nil {
-			return err
-		}
+	const failedHtlcsOnly = true
+	err := p.DeletePayment(ctx, hash, failedHtlcsOnly)
+	if err != nil {
+		return err
 	}
 
 	return nil