PWA-805: Expose localization system / store config from GraphQL

Author: eug123

app/code/Magento/Store/Model/ResourceModel/StoreWebsiteRelation.php

@@ -48,11 +48,11 @@ public function getStoreByWebsiteId($websiteId)
      * Get website store data
      *
      * @param int $websiteId
-     * @param int $storeGroupId
      * @param bool $available
+     * @param int|null $storeGroupId
      * @return array
      */
-    public function getWebsiteStores(int $websiteId, int $storeGroupId = null, bool $available = false): array
+    public function getWebsiteStores(int $websiteId, bool $available = false, int $storeGroupId = null): array
     {
         $connection = $this->resource->getConnection();
         $storeTable = $this->resource->getTableName('store');

app/code/Magento/StoreGraphQl/Model/Resolver/Store/StoreConfigDataProvider.php

@@ -78,7 +78,7 @@ public function getStoreConfigData(StoreInterface $store): array
      */
     public function getAvailableStoreConfig(int $websiteId, int $storeGroupId = null): array
     {
-        $websiteStores = $this->storeWebsiteRelation->getWebsiteStores($websiteId, $storeGroupId, true);
+        $websiteStores = $this->storeWebsiteRelation->getWebsiteStores($websiteId, true, $storeGroupId);
         $storeCodes = array_column($websiteStores, 'code');
 
         $storeConfigs = $this->storeConfigManager->getStoreConfigs($storeCodes);