paymentsdb: rename paymentsBatchData

We rename this variable to paymentsDetailsData because we will
also need to batch load the core payment and intent data in
future commits and this renaming should make it clear that this
does match payment related data but not the core data which is
in the payment and in the intent table.

payments/db/sql_store.go

@@ -161,8 +161,11 @@ func fetchPaymentWithCompleteData(ctx context.Context,
 	return buildPaymentFromBatchData(dbPayment, batchData)
 }
 
-// paymentsBatchData holds all the batch-loaded data for multiple payments.
+// paymentsDetailsData holds all the batch-loaded data for multiple payments.
-type paymentsBatchData struct {
+// This does not include the core payment and intent data which is fetched
+// separately. It includes the additional data like attempts, hops, hop custom
+// records, and route custom records.
+type paymentsDetailsData struct {
 	// paymentCustomRecords maps payment ID to its custom records.
 	paymentCustomRecords map[int64][]sqlc.PaymentFirstHopCustomRecord
 
@@ -185,7 +188,7 @@ type paymentsBatchData struct {
 // the given payment IDs.
 func loadPaymentCustomRecords(ctx context.Context,
 	cfg *sqldb.QueryConfig, db SQLQueries, paymentIDs []int64,
-	batchData *paymentsBatchData) error {
+	batchData *paymentsDetailsData) error {
 
 	return sqldb.ExecuteBatchQuery(
 		ctx, cfg, paymentIDs,
@@ -219,7 +222,7 @@ func loadPaymentCustomRecords(ctx context.Context,
 // payment IDs.
 func loadHtlcAttempts(ctx context.Context, cfg *sqldb.QueryConfig,
 	db SQLQueries, paymentIDs []int64,
-	batchData *paymentsBatchData) ([]int64, error) {
+	batchData *paymentsDetailsData) ([]int64, error) {
 
 	var allAttemptIndices []int64
 
@@ -252,7 +255,7 @@ func loadHtlcAttempts(ctx context.Context, cfg *sqldb.QueryConfig,
 // It uses a batch query to fetch all hops for the given attempt indices.
 func loadHopsForAttempts(ctx context.Context, cfg *sqldb.QueryConfig,
 	db SQLQueries, attemptIndices []int64,
-	batchData *paymentsBatchData) ([]int64, error) {
+	batchData *paymentsDetailsData) ([]int64, error) {
 
 	var hopIDs []int64
 
@@ -285,7 +288,7 @@ func loadHopsForAttempts(ctx context.Context, cfg *sqldb.QueryConfig,
 // loadHopCustomRecords loads hop-level custom records for all hops. It uses
 // a batch query to fetch all custom records for the given hop IDs.
 func loadHopCustomRecords(ctx context.Context, cfg *sqldb.QueryConfig,
-	db SQLQueries, hopIDs []int64, batchData *paymentsBatchData) error {
+	db SQLQueries, hopIDs []int64, batchData *paymentsDetailsData) error {
 
 	return sqldb.ExecuteBatchQuery(
 		ctx, cfg, hopIDs,
@@ -320,7 +323,7 @@ func loadHopCustomRecords(ctx context.Context, cfg *sqldb.QueryConfig,
 // attempt indices.
 func loadRouteCustomRecords(ctx context.Context, cfg *sqldb.QueryConfig,
 	db SQLQueries, attemptIndices []int64,
-	batchData *paymentsBatchData) error {
+	batchData *paymentsDetailsData) error {
 
 	return sqldb.ExecuteBatchQuery(
 		ctx, cfg, attemptIndices,
@@ -349,9 +352,9 @@ func loadRouteCustomRecords(ctx context.Context, cfg *sqldb.QueryConfig,
 // loadPaymentsBatchData loads all related data for multiple payments in batch.
 // It uses a batch queries to fetch all data for the given payment IDs.
 func loadPaymentsBatchData(ctx context.Context, cfg *sqldb.QueryConfig,
-	db SQLQueries, paymentIDs []int64) (*paymentsBatchData, error) {
+	db SQLQueries, paymentIDs []int64) (*paymentsDetailsData, error) {
 
-	batchData := &paymentsBatchData{
+	batchData := &paymentsDetailsData{
 		paymentCustomRecords: make(
 			map[int64][]sqlc.PaymentFirstHopCustomRecord,
 		),
@@ -425,7 +428,7 @@ func loadPaymentsBatchData(ctx context.Context, cfg *sqldb.QueryConfig,
 // buildPaymentFromBatchData builds a complete MPPayment from a database payment
 // and pre-loaded batch data.
 func buildPaymentFromBatchData(dbPayment sqlc.PaymentAndIntent,
-	batchData *paymentsBatchData) (*MPPayment, error) {
+	batchData *paymentsDetailsData) (*MPPayment, error) {
 
 	// The query will only return BOLT 11 payment intents or intents with
 	// no intent type set.
@@ -559,7 +562,7 @@ func (s *SQLStore) QueryPayments(ctx context.Context, query Query) (Response,
 
 		// batchDataFunc loads all related data for a batch of payments.
 		batchDataFunc := func(ctx context.Context, paymentIDs []int64) (
-			*paymentsBatchData, error) {
+			*paymentsDetailsData, error) {
 
 			return loadPaymentsBatchData(
 				ctx, s.cfg.QueryCfg, db, paymentIDs,
@@ -570,7 +573,7 @@ func (s *SQLStore) QueryPayments(ctx context.Context, query Query) (Response,
 		// data.
 		processPayment := func(ctx context.Context,
 			dbPayment sqlc.FilterPaymentsRow,
-			batchData *paymentsBatchData) error {
+			batchData *paymentsDetailsData) error {
 
 			// Build the payment from the pre-loaded batch data.
 			mpPayment, err := buildPaymentFromBatchData(