fix(encryption): Give GroupKey same interface as protocol's EncryptedGroupKey.

Fixes streamr-client-testing subscriber.js.

Author: timoxley

src/stream/Encryption.ts

@@ -135,6 +135,14 @@ class GroupKey {
         return this.id
     }
 
+    toArray() {
+        return [this.id, this.hex]
+    }
+
+    serialize() {
+        return JSON.stringify(this.toArray())
+    }
+
     static generate(id = uuid('GroupKey')) {
         const keyBytes = crypto.randomBytes(32)
         return new GroupKey(id, keyBytes)

src/subscribe/index.ts

@@ -418,7 +418,6 @@ class Subscriptions {
         const sub = new Subscription(this.client, {
             ...options,
             validate: subSession.validate,
-        // @ts-expect-error
         }, async (err: Todo) => {
             try {
                 await this.remove(sub)