feat: add support for variable sleep durations

[pimlie]

This PR adds support to configure different sleep durations per day-of-week, hour and minute. It should basically support the most common configs as is described in hass.md, so instead of using home-assistant to keep changing the sleep duration it's just baked into the homeplate fw :)

• see config_example.cpp for example config
• I had to change the env's a little bit to be able to run the unit tests