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/ActionBar.jsx

@@ -13,7 +13,7 @@ import session from "../app/Session";
 import logo from "../img/ntfy.svg";
 import subscriptionManager from "../app/SubscriptionManager";
 import routes from "./routes";
-import db from "../app/db";
+import getDb from "../app/getDb";
 import { topicDisplayName } from "../app/utils";
 import Navigation from "./Navigation";
 import accountApi from "../app/AccountApi";
@@ -120,8 +120,10 @@ const ProfileIcon = () => {
 
   const handleLogout = async () => {
     try {
+      await subscriptionManager.unsubscribeAllWebPush();
+
       await accountApi.logout();
-      await db.delete();
+      await getDb().delete();
     } finally {
       session.resetAndRedirect(routes.app);
     }