Enable wifi disconnect/reconnect on purpose to reduce wifi congestion

**Describe the problem you have/What new integration you would like**

I would like my Esphome devices to disconnect/reconnect from/to wifi on purpuse, to prevent wifi congestion.

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

Some of my Esphome devices control relays (several Sonoff minis), so a deep sleep wouldn't help in this case as the signal is cut from the relays during deep sleep.
Also, I have a Max7219 dot matrix clock that still needs to display time, but not necessarily stay on wifi 24/7

**Additional context**

Start by reviewing the existing ESPHome Wi-Fi and deep-sleep behavior, considering the relay-controlled Sonoff minis and the MAX7219 clock described in issue #1129. Done would mean devices can intentionally disconnect and reconnect from Wi-Fi to reduce congestion while their local relay and display functions continue as needed.

Written by the indexing model from the issue text.