Add PWA, service worker and Web Push

- Use new notification request/opt-in flow for push
- Implement unsubscribing
- Implement muting
- Implement emojis in title
- Add iOS specific PWA warning
- Don’t use websockets when web push is enabled
- Fix duplicate notifications
- Implement default web push setting
- Implement changing subscription type
- Implement web push subscription refresh
- Implement web push notification click

web/src/components/App.jsx

@@ -57,6 +57,10 @@ const App = () => {
 
 const updateTitle = (newNotificationsCount) => {
   document.title = newNotificationsCount > 0 ? `(${newNotificationsCount}) ntfy` : "ntfy";
+
+  if ("setAppBadge" in window.navigator) {
+    window.navigator.setAppBadge(newNotificationsCount);
+  }
 };
 
 const Layout = () => {