Expose HSM status as an input select

[amosyuen]

Currently it uses a sensor to read the state and a service to set it. But I think it would be easier to use if you use an input select. It also matches how the hub mode is exposed.

[jason0x43]

I agree, it would be a bit easier to use. It hasn't been implemented yet because HSM is a bit more complex than modes, but it's certainly doable.

Notes: The set of possible modes is listed in the docs, although I'm not sure I entirely trust that without more testing. The status values and values used to change the status aren't symmetric ("armedAway" vs "armed away"), and I think some potentially status values ("disarmed") have no equivalent status values (at least, there's no equivalent in the official list of possible states).