MC-41473: Subcategory order changes not correct in Graphql

Author: tsviklinskyi

app/code/Magento/CatalogGraphQl/Model/Resolver/Products/DataProvider/ExtractDataFromCategoryTree.php

@@ -67,7 +67,8 @@ public function execute(\Iterator $iterator): array
                 $tree = $this->mergeCategoriesTrees($currentLevelTree, $tree);
             }
         }
-        return $tree;
+
+        return $this->sortTree($tree);
     }
 
     /**
@@ -141,4 +142,24 @@ private function explodePathToArray(array $pathElements, int $index): array
         }
         return $tree;
     }
+
+    /**
+     * Recursive method to sort tree
+     *
+     * @param array $tree
+     * @return array
+     */
+    private function sortTree(array $tree): array
+    {
+        foreach ($tree as &$node) {
+            if ($node['children']) {
+                uasort($node['children'], function ($element1, $element2) {
+                    return $element1['position'] > $element2['position'];
+                });
+                $node['children'] = $this->sortTree($node['children']);
+            }
+        }
+
+        return $tree;
+    }
 }