refactor: Use ESM (#8358)

* wip

* wip

* fix

* clean up

* Update tsconfig.json

* Update activitypub.ts

* wip

packages/backend/src/server/proxy/index.ts

@@ -2,10 +2,10 @@
  * Media Proxy
  */
 
-import * as Koa from 'koa';
-import * as cors from '@koa/cors';
-import * as Router from '@koa/router';
-import { proxyMedia } from './proxy-media';
+import Koa from 'koa';
+import cors from '@koa/cors';
+import Router from '@koa/router';
+import { proxyMedia } from './proxy-media.js';
 
 // Init app
 const app = new Koa();
@@ -23,4 +23,4 @@ router.get('/:url*', proxyMedia);
 // Register router
 app.use(router.routes());
 
-module.exports = app;
+export default app;