Add reply_id and is_tapback

mesh.proto

@@ -524,6 +524,17 @@ message Data {
    * Indicates the original message ID that this message is reporting failure on. (formerly called original_id)
    */
   fixed32 request_id = 6;
+
+  /*
+   * If set, this message is intened to be a reply to a previously sent message with the defined id.
+   */
+  fixed32 reply_id = 7;
+
+   /*
+    * Defaults to false. If true, then what is in the payload should be treated as an emoji like giving
+    * a message a heart or poop emoji.
+    */
+  bool is_tapback = 8;
 }
 
 /*