feat: remove Cache API, rework preload(), cancel() and fetch() (#25289)

* feat: remove Cache API, rework preload(), cancel() and fetch()

perf - replace broadcast channel with direct postMessage

* remove sw response handling

* review comments

web/src/service-worker/messaging.ts

@@ -0,0 +1,33 @@
+/// <reference types="@sveltejs/kit" />
+/// <reference no-default-lib="true"/>
+/// <reference lib="esnext" />
+/// <reference lib="webworker" />
+
+import { handleCancel } from './request';
+
+const sw = globalThis as unknown as ServiceWorkerGlobalScope;
+
+export const installMessageListener = () => {
+  sw.addEventListener('message', (event) => {
+    if (!event.data?.type) {
+      return;
+    }
+
+    switch (event.data.type) {
+      case 'cancel': {
+        const url = event.data.url ? new URL(event.data.url, self.location.origin) : undefined;
+        if (!url) {
+          return;
+        }
+
+        const client = event.source;
+        if (!client) {
+          return;
+        }
+
+        handleCancel(url);
+        break;
+      }
+    }
+  });
+};