Support arbitrary light for status_led

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

The [M5Stack Pico mate](https://shop.m5stack.com/products/m5stamp-pico-mate-with-pin-headers) has a SK6812 LED onboard but no other LED. So it is impossible to use the [status_led light component](https://esphome.io/components/light/status_led.html).


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

It'd be nice if we could use the onboard RGB led as a status LED.

I think it'd be better to simply make status_led more generic than do a one-off to support a SK6812 specifically.

**Additional context**

I took a quick look at the code and there's no way at the moment hook events when STATUS_LED_ERROR or STATUS_LED_WARNING are set. I suspect this feature request would require some deep internal refactoring inside https://github.com/esphome/esphome/blob/dev/esphome/core/component.cpp.

Start with the status_led light component and esphome/core/component.cpp, focusing on how STATUS_LED_ERROR and STATUS_LED_WARNING are set and propagated. The work is done when status_led can use the onboard SK6812 or another arbitrary light through a generic mechanism, with the relevant status behavior covered.

Written by the indexing model from the issue text.