Dynamic API routes (#836)

* Add dynamic API endpoints

* Add missing dependency

* Update api handlers

* Updates

* Fix build errors

* Update package.json

* Add checkout endpoint parser & update errors

* Update tsconfig.json

* Update cart.ts

* Update parser

* Update errors.ts

* Update errors.ts

* Move to Edge runtime

* Revert to local

* Fix switchable runtimes

* Make nodejs default runtime

* Update pnpm-lock.yaml

* Update handlers

* Fix build errors

* Change headers

packages/sfcc/src/api/utils/fetch-local.ts

@@ -1,17 +1,15 @@
 import { FetcherError } from '@vercel/commerce/utils/errors'
 import type { GraphQLFetcher } from '@vercel/commerce/api'
 import type { SFCCConfig } from '../index'
-import fetch from './fetch'
 
 const fetchGraphqlApi: (getConfig: () => SFCCConfig) => GraphQLFetcher =
   (getConfig) =>
-  async (query: string, { variables, preview } = {}, fetchOptions) => {
+  async (query: string, { variables, preview } = {}, headers?: HeadersInit) => {
     const config = getConfig()
     const res = await fetch(config.commerceUrl, {
-      ...fetchOptions,
       method: 'POST',
       headers: {
-        ...fetchOptions?.headers,
+        ...headers,
         'Content-Type': 'application/json',
       },
       body: JSON.stringify({