fix: Add protocolMessageKey and fix revoked messages to preserve original before.id (#3715)

* Add protocolMessageKey and fix revoke

* Add protocolMessageKey and fix revoke

* docs: add explanation

src/structures/Message.js

@@ -258,6 +258,14 @@ class Message extends Base {
             this.latestEditMsgKey = data.latestEditMsgKey;
         }
         
+        /**
+         * Protocol message key.
+         * Can be used to retrieve the ID of an original message that was revoked.
+         */
+        if (data.protocolMessageKey) {
+            this.protocolMessageKey = data.protocolMessageKey;
+        }
+
         /**
          * Links included in the message.
          * @type {Array<{link: string, isSuspicious: boolean}>}