Plugwise

- Code quality improvements.

- As per Core deprecation of python 3.8, removed CI/CD testing and bumped pypi to 3.9 and production.
- Add support for Stretch with fw 2.7.18.

- **BREAKING**: Change active device detection, detect both OpenTherm (replace Auxiliary) and OnOff (new) heating and cooling devices.
- Stretch: base detection on the always present Stick
- Add Adam v3.6.x (beta) and Anna firmware 4.2 support (representation and switching on/off of a schedule has changed)
- Anna: Fix cooling_active prediction
- Schedules: always show `available_schemas` and `selected_schema`, also with "None" available and/or selected
- Cleanup and optimize code
- Adapt and improve testcode

- Change from list- to dict-format for binary_sensors, sensors and switches
- Provide gateway-devices for Legacy Anna and Stretch
- Code-optimizations

- Anna: add two sensors related to automatic switching between heating and cooling and add a heating/cooling-mode active indication
- Adam: also provide a heating/cooling-mode active indication
- Fixing 171
- Improved dependency handling (dependabot)

- Adam: collect `control_state` from master thermostats, allows showing the thermostat state as on the Plugwise App
- Adam: collect `allowed_modes` and look for `cooling`, indicating cooling capability being available
- Optimize code: use `_all_appliances()` once instead of 3 times, by updating/changing `single_master_thermostat()`,
- Protect several more variables,
- Change/improve how `illuminance` and `outdoor_temperature` are obtained,
- Use walrus operator where applicable,
- Various small code improvements,
- Add and adapt testcode
- Add testing for python 3.10, improve dependencies (github workflow)
- Bump aiohttp to 3.8.1, remove fixed dependencies