Comet Blue Thermostatic Radiator Valve support

[GrumpyMeow]

Hi Ayufan,

I've created an implementation for controlling Comet Blue TRV's based upon your code. I think it would help users if my implementation gets merged into your repo.

Unfortunatly i had to make some small changes on the code, because i didn't know how to make a correction implementation. Could you maye help me out with this?

thanks in advance, Sander