Support fallback IP address

[elahd]

I have a tablet that's connected to my home network via Ethernet and WiFi. I like keeping it this way for redundancy, but the tablet's OS switches back and forth between both connections as it sees fit. The fully kiosk integration is configured using the Ethernet adapter's IP address, meaning that the integration goes offline whenever the tablet uses its WiFi connection. I don't want to set up two versions of the same tablet in Home Assistant.

I'm proposing that this integration should support a primary and fallback IP addresses for each device and that, for convenience, these settings be configurable through the integration's "Options" function instead of through "Configuration". This would make it possible to edit these settings without reinstalling the integration.

I'm willing to do the work, I'm really just looking for a sign off from @cgarwood before I start so the work doesn't go to waste.