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

server/util.go

@@ -2,6 +2,8 @@ package server
 
 import (
 	"context"
+	_ "embed" // required by go:embed
+	"encoding/json"
 	"fmt"
 	"heckel.io/ntfy/util"
 	"io"
@@ -133,3 +135,25 @@ func maybeDecodeHeader(header string) string {
 	}
 	return decoded
 }
+
+var (
+	//go:embed "mailer_emoji_map.json"
+	emojisJSON string
+)
+
+func toEmojis(tags []string) (emojisOut []string, tagsOut []string, err error) {
+	var emojiMap map[string]string
+	if err = json.Unmarshal([]byte(emojisJSON), &emojiMap); err != nil {
+		return nil, nil, err
+	}
+	tagsOut = make([]string, 0)
+	emojisOut = make([]string, 0)
+	for _, t := range tags {
+		if emoji, ok := emojiMap[t]; ok {
+			emojisOut = append(emojisOut, emoji)
+		} else {
+			tagsOut = append(tagsOut, t)
+		}
+	}
+	return
+}