need json feature

The Python-MySQL Replication project is designed to convert binlog events generated by the MySQL replication protocol into Python objects. As these objects are delivered to users in Python, they can be transformed flexibly according to the users' needs. However, in most cases, it has been observed that companies tend to convert these objects into JSON format for their use.

* [Case. 1 Streaming Changes in a Database with Amazon Kinesis](https://aws.amazon.com/ko/blogs/database/streaming-changes-in-a-database-with-amazon-kinesis/)
* [Case. 2 - LOMIO (MySQL-to-Kafka)](https://elseif.kakao.com/2020/session/99)

I think JSON feature within the event class to accommodate user needs! Although the feature can be implemented simply, i believe it to be a valuable contribution that sufficiently reflects the needs of our users.

Start by locating the event classes that expose binlog data and inspect how their Python objects are currently represented or serialized. Check existing tests around event output; done should be a defined, tested JSON representation for the relevant event objects, though this issue does not name specific files or tests.

Written by the indexing model from the issue text.