Contact Sensor for Lame Unifi API error: Unable to connect to the Protect controller.
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**Is your feature request related to a problem? Please describe:**
The lame unifi stacking (at least in my case) has plagued me with `API error: Unable to connect to the Protect controller.`, but I don't know when this has happened until there was a missed notification event and I try and figure out why. 

**Describe the solution you'd like:**
I'd like to request a contact sensor switch that gets toggled when this error/situation is encountered. 

**Describe alternatives you've considered:**
I've considered scheduling controller reboots, but sometimes it is required more frequently than expected. With the contact switch, I adopt and as-needed approach. 

**Additional context:**
Thank you for your time and consideration. And thank you for being so awesome! I've tried a few projects out there, and the design and easy of use for this one is freaking unbelievable.  
