use URLsearchParams class from nodejs api to fix error.

Author: HugoMario

src/main/resources/handlebars/typescript-fetch/api.mustache

@@ -106,7 +106,7 @@ export const {{classname}}FetchParamCreator = function (configuration?: Configur
             const localVarHeaderParameter = {} as any;
             const localVarQueryParameter = {} as any;
     {{#hasFormParams}}
-            const localVarFormParams = new url.URLSearchParams();
+            const localVarFormParams = new URLSearchParams();
     {{/hasFormParams}}
 
     {{#authMethods}}