B2B-2677: [MediaGallery] Implement data caching for GraphQL results on resolver level

- Assert default store's cache record entry's label is not null

Author: danmooney2

dev/tests/api-functional/testsuite/Magento/GraphQl/Catalog/ResolverCache/MediaGalleryTest.php

@@ -214,6 +214,9 @@ public function testResolverCacheRecordIsCreatedForEachStoreView()
         $cacheKeyInDefaultStoreView = $this->getCacheKeyForMediaGalleryResolver($product);
         $this->assertMediaGalleryResolverCacheRecordExists($product);
 
+        $cacheEntryInDefaultStoreView = $this->graphQlResolverCache->load($cacheKeyInDefaultStoreView);
+        $this->assertNotNull(json_decode($cacheEntryInDefaultStoreView, true)[0]['label']);
+
         // Switch to second store view
         $this->storeManager->setCurrentStore($store2->getCode());