Fix grave ReferenceError: fetch is not defined error (#1460)

* use cross-fetch

* remove from utils usage

src/server/handlers/catch-all-handler.tsx

@@ -1,5 +1,6 @@
 import { initializeSite, isAuthPath } from "@utils/app";
 import { ErrorPageData } from "@utils/types";
+import fetch from "cross-fetch";
 import type { Request, Response } from "express";
 import { StaticRouter, matchPath } from "inferno-router";
 import { renderToString } from "inferno-server";

src/server/handlers/manifest-handler.ts

@@ -1,3 +1,4 @@
+import fetch from "cross-fetch";
 import type { Request, Response } from "express";
 import { LemmyHttp } from "lemmy-js-client";
 import { getHttpBaseExternal, getHttpBaseInternal } from "../../shared/env";

src/server/utils/fetch-icon-png.ts

@@ -1,3 +1,5 @@
+import fetch from "cross-fetch";
+
 export async function fetchIconPng(iconUrl: string) {
   return await fetch(iconUrl)
     .then(res => res.blob())