* Add support for controlling homekit lights and switches
This adds support for controlling lights and switches that expose a HomeKit
control interface, avoiding the requirement to implement protocol-specific
components.
* Comment out the homekit requirement
This needs to build native code, so leave it commented for now
* Review updates
* Make HomeKit auto-discovery optional
Add an "enable" argument to the discovery component and add a list of
optional devices types (currently just HomeKit) to discover
* Further review comments
* Update requirements_all.txt
* Fix houndci complaints
* Further review updates
* Final review fixup
* Lint fixups
* Fix discovery tests
* Further review updates
* Don't initialize components which have already been discovered (fixes#5588)
* Don't log that we've found a service unless we know it's not a duplicate
* Encode discovery data hash with JSON
This also solves the issue of trying to hash non-hashable objects like dicts
* Add test for duplicate device discovery
