Replace 'appID' with server name or IP

the appID is not useful to the humans (I realize it is useful to Stork). the human will be thinking of the Application by hostname or IP address. We need some naming scheme that is also implemented on the Kea server, so the same name can be observed on Kea either directly or via Stork. One possibility is to have Stork get some sort of dhcp server 'name' from the Kea server. this could be a dns name but doesn't have to be.

Both users we tested with so far remarked that they didn't know what appID was or how to use it, and they were both searching for some key to associate a Kea server across multiple panels.