feat: Convert several batch methods to the standardized format (#7116)

integration-tests/api/__tests__/admin/reservations/index.spec.ts

@@ -318,9 +318,9 @@ medusaIntegrationTestRunner({
             scId = scResponse.data.sales_channel.id
 
             await api.post(
-              `/admin/stock-locations/${location}/sales-channels/batch/add`,
+              `/admin/stock-locations/${location}/sales-channels`,
               {
-                sales_channel_ids: [scId],
+                add: [scId],
               },
               adminHeaders
             )