Add snapshot testing tool to catch breaking changes in events

[oskardudycz]

Some inspiration from Verify, so storing Jason payloads, or maybe some static analysis like Dennis Doomen shown in his talk with files generator.

[oskardudycz]

It sounds like Node.js Native Test Runner has a built-in tool for snapshot testing, sounds like a good candidate to use internally! https://nodejs.org/api/test.html#snapshot-testing 🤞