Added support for Aqara single gang switch

[markiboy2all]

tested using conbee II usb dongle and Domoticz running on Raspberry PI 3.
changes make it possible to detect hold event and the selector levels now have friendly names.

[Smanar]

Hello, you realy don't like the generic one ^^ ?

You are conscient this modification will make script already made incompatible with next version ? B1 will be the same, but not other.

BTW, there is no problem for me just :

• Can you pls remove the debug line at 490
• Make the PR on the bera branch, I have just updated the master 1 week ago.

Thx.

[Smanar]

@markiboy2all are you still here ?

[Smanar]

And what is the problem with heartbeat ? 10s is not good ?

[markiboy2all]

@Smanar Hi sorry was not able to get back to this until today. the heartbeat selector was a test because my aqara switches took quite some time to get out of their 'click', 'double click', and 'hold' states back to off. This was actually only annoying using the 'hold' state to dim the lights as dimming would continue after letting the button go. therefore i increased the heartbeat. made it into a selector as it might not be handy for everyone. I will close this pull request and make a new one for your beta branch. and i apologize for this pull request. im a little new to github and made a mistake.