M5Stack 4 relays request

**Describe the problem you have/What new integration you would like**
I have recently bought the M5Stack 4 relays unit. I have already build some custom code for myself and that works. However I thought that others might benefit from this as well. So perhaps this code (with improvements from others of course) can be implemented into ESPHome.

This is the unit itself:
https://docs.m5stack.com/en/unit/4relay

This is my github:
https://github.com/KoenBreeman/ESPHome

**Please describe your use case for this integration and alternatives you've tried:**

It’s sets up 4 switches which can be used. Perhaps my code can better be set up. Perhaps it’s better to use a hub and set up the switch to have a channel. But I leave that up to the developers.

**Additional context**

Start by reviewing the linked M5Stack 4-relay documentation and the reporter's custom code repository. Determine how the integration should fit ESPHome and whether it should expose four switches directly or use a hub/channel model; done means the M5Stack unit is supported with its four relay switches.

Written by the indexing model from the issue text.