Curtain BLE designation of dual vs single curtain setup

[apollo1220]

Current Situation

Currently there doesn't seem to be a way to know whether the curtain device is setup just as a single curtain or is paired with another curtain device to make a dual curtain.

Proposed Change

Add information to the GET API which designates which way the curtain device is configured.

Additional Context

This is for Home Assistant's integration with SwitchBot.

[bdraco]

We likely need a way in the advertisement data to know which commands to send

If its a dual setup we likely need to send the original commands that https://github.com/Danielhiversen/pySwitchbot/pull/122/files changed.

If its a single setup we need to use the commands that are in there right now

[donavanbecker]

If you use with OpenAPI then you can see if it is paired with another curtain. That's what I do in the homebridge plugin.

[bdraco]

Unfortunately Home Assistant only talks to these over Bluetooth so it has no credentials to access the cloud apis