[openapi v3.1] Preserve property item keys

This is mainly useful when dealing with webhooks to use the array index
as a name for the given webhook as the spec uses it as a unique
identifier: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#openapi-object

Author: WyriHaximus

src/SpecBaseObject.php

@@ -86,22 +86,22 @@ public function __construct(array $data)
                         } else {
                             // array
                             $this->_properties[$property] = [];
-                            foreach ($data[$property] as $item) {
+                            foreach ($data[$property] as $key => $item) {
                                 if ($type[0] === Type::STRING) {
                                     if (!is_string($item)) {
                                         $this->_errors[] = "property '$property' must be array of strings, but array has " . gettype($item) . " element.";
                                     }
-                                    $this->_properties[$property][] = $item;
+                                    $this->_properties[$property][$key] = $item;
                                 } elseif (Type::isScalar($type[0])) {
-                                    $this->_properties[$property][] = $item;
+                                    $this->_properties[$property][$key] = $item;
                                 } elseif ($type[0] === Type::ANY) {
                                     if (is_array($item) && isset($item['$ref'])) {
-                                        $this->_properties[$property][] = new Reference($item, null);
+                                        $this->_properties[$property][$key] = new Reference($item, null);
                                     } else {
-                                        $this->_properties[$property][] = $item;
+                                        $this->_properties[$property][$key] = $item;
                                     }
                                 } else {
-                                    $this->_properties[$property][] = $this->instantiate($type[0], $item);
+                                    $this->_properties[$property][$key] = $this->instantiate($type[0], $item);
                                 }
                             }
                         }