Add support for HomeKit motion sensor devices

[Jc2k]

Description:

Add support for polling HomeKit motion sensors.

I'm testing with an Eve Motion (on my bluetooth branch) and a homekit_python demoserver accessory based on the HAP spec (page 225). A HomeKit motion sensor will have a service of type public.hap.service.sensor.motion with a single required characteristic of public.hap.characteristic.motion-detected which is a bool. The characteristic will be set to true after motion is detected and will return to false after a minute or so with no motion detected. (In the case of the Eve Motion you can tweak this duration in the app).

Related issue (if applicable): fixes #

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#8332

Example entry for configuration.yaml (if applicable):

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[MartinHjelmare]

This check isn't necessary. It will be handled by the base entity class.

[Jc2k]

Opened #20568 to make sure this isn't lost.