* Best effort state initialization of bayesian binary sensor.
Why:
* https://github.com/home-assistant/home-assistant/issues/30119
This change addresses the need by:
* Running the main update logic eagerly for each entity being observed
on `async_added_to_hass`.
* Test of the new behavior.
* Refactor in order to reduce number of methods with side effects that
mutate instance attributes.
* Improve test coverage
Why:
* Because for some reason my commits decreased test coverage.
This change addresses the need by:
* Adding coverage for the case where a device returns `STATE_UNKNOWN`
* Adding coverage for configurations with templates
* rebase and ensure upstream tests passed
* Delete commented code from addressing merge conflict.
dd1608db0d