fetchWorker: support RequestInit

src/workers/fetch.worker.ts

@@ -1,8 +1,14 @@
 import { Comlink } from '@/deps.ts';
 
+import './handlers/abortsignal.ts';
+
 export const FetchWorker = {
-  async fetch(url: string): Promise<[BodyInit, ResponseInit]> {
-    const response = await fetch(url);
+  async fetch(
+    url: string,
+    init: Omit<RequestInit, 'signal'>,
+    signal: AbortSignal | null | undefined,
+  ): Promise<[BodyInit, ResponseInit]> {
+    const response = await fetch(url, { ...init, signal });
     return [
       await response.text(),
       {