Adds auto-off implementation. The feature stays enabled after the timer runs out, and it will start the countdown if the device is turned on again without explicitly disabling it.
New features:
* Switch to select if enabled: `Auto off enabled (auto_off_enabled): False`
* Setting to change the delay: `Auto off minutes (auto_off_minutes): 222`
* If timer is active, datetime object when the device gets turned off: `Auto off at (auto_off_at): None`
The initial steps to modularize the smartdevice. Modules are initialized based on the component negotiation, and each module can indicate which features it supports and which queries should be run during the update cycle.
