MC-21480: Add caching for CategoryList resolver

- Added CategoryList Caching resolver

Author: avattam06

app/code/Magento/CatalogGraphQl/Model/Resolver/Category/CategoryListIdentity.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Resolver\Category;
+
+use Magento\Framework\GraphQl\Query\Resolver\IdentityInterface;
+
+/**
+ * Identity for resolved category
+ */
+class CategoryListIdentity implements IdentityInterface
+{
+    /** @var string */
+    private $cacheTag = \Magento\Catalog\Model\Category::CACHE_TAG;
+
+    /**
+     * Get category IDs from resolved data
+     *
+     * @param array $resolvedData
+     * @return string[]
+     */
+    public function getIdentities(array $resolvedData): array
+    {
+        $ids = [];
+        if (!empty($resolvedData)) {
+            foreach ($resolvedData as $category) {
+                $ids[] = sprintf('%s_%s', $this->cacheTag, $category['id']);
+            }
+            if (!empty($ids)) {
+                array_unshift($ids, $this->cacheTag);
+            }
+        }
+        return $ids;
+    }
+}

app/code/Magento/CatalogGraphQl/etc/schema.graphqls

@@ -16,7 +16,7 @@ type Query {
     @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\CategoryTree") @doc(description: "The category query searches for categories that match the criteria specified in the search and filter attributes.") @deprecated(reason: "Use 'categoryList' query instead of 'category' query") @cache(cacheIdentity: "Magento\\CatalogGraphQl\\Model\\Resolver\\Category\\CategoryTreeIdentity")
     categoryList(
     filters: CategoryFilterInput @doc(description: "Identifies which Category filter inputs to search for and return.")
-    ): [CategoryTree] @doc(description: "Returns an array of categories based on the specified filters.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\CategoryList")
+    ): [CategoryTree] @doc(description: "Returns an array of categories based on the specified filters.") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\CategoryList") @cache(cacheIdentity: "Magento\\CatalogGraphQl\\Model\\Resolver\\Category\\CategoryListIdentity")
 }
 
 type Price @doc(description: "Price is deprecated, replaced by ProductPrice. The Price object defines the price of a product as well as any tax-related adjustments.") {