channeldb: add context to query method

We add a context for the query method because the query method
is part of the paymentDB interface and for the SQL case
we will need the context for this method because the native
SQL drivers demand one. So we add it for the kv implementation
here as well so we can then make use of the new interface type.

channeldb/payments_kv_store.go

@@ -2,6 +2,7 @@ package channeldb
 
 import (
 	"bytes"
+	"context"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -1206,8 +1207,8 @@ func fetchFailedHtlcKeys(bucket kvdb.RBucket) ([][]byte, error) {
 // QueryPayments is a query to the payments database which is restricted
 // to a subset of payments by the payments query, containing an offset
 // index and a maximum number of returned payments.
-func (p *KVPaymentsDB) QueryPayments(query PaymentsQuery) (PaymentsResponse,
-	error) {
+func (p *KVPaymentsDB) QueryPayments(_ context.Context,
+	query PaymentsQuery) (PaymentsResponse, error) {
 
 	var resp PaymentsResponse