Plugwise

- Refactor Smile-related code:
- Implement Core `EntityDescription`-updates including `entity_category`.
- Link to plugwise module [v0.15.2](https://github.com/plugwise/python-plugwise/releases/tag/v0.15.2)
- Move testfixtures into tests/components/plugwise directory.
- Various test-related fixes.

- Anna: replace `setpoint` with `setpoint_low` and `setpoint_high` when cooling is active
- Anna: update according to recent Anna-with-cooling firmware updates (info provided by Plugwise)
- Anna: handle `cooling_state = on` according to Plugwise specification (`cooling_state = on` and `modulation_level = 100`)
- Move boiler-type detection and cooling-present detection into `_all_device_data()`
- Update/extend testing and corresponding userdata

- [192](https://github.com/plugwise/python-plugwise/issues/192)

- Update `_last_used_schedule()`: provide the collected schedules as input in order to find the last-modified valid schedule.
- `_rule_ids_by_x()`: replace None by NONE, allowing for simpler typing.
- Remove `schedule_temperature` from output: for Adam the schedule temperature cannot be collected when a schedule is not active.
- Simplify `_schedules()`, don't collect the schedule-details as no longer required.
- Improve solution for plugwise-beta issue 276
- Move HA Core input-checks into the backend library (into set_schedule_state() and set_preset())

- [276](https://github.com/plugwise/plugwise-beta/issues/276)