Add remote arp option

[xMikooo]

In my enviroment I don't run the controller on my main router since I do not use OpenWRT as a gateway, only as a dumb AP software. Personally I use OPNsense but other linux/bsd based solutions are also popular. Because of that I only get mac addresses of devices connected to APs on the controller. Since the project already has a way to execute ssh command directly. It would be nice to specify the device on which arp -a is executed. Pretty much all linux/bsd has the same output of this command, thus parsing would be easy.

[obsy]

You can define your own commands sent to the AP, so you can also do arp -a if you need it.

[xMikooo]

I don't think you quite understood me. Now the plugin displays ip address / hostname, based on arp table from client's mac address. I don't run my main gateway on openwrt and I know quite a few people that also do not, but they run their APs on OpenWRT. Because of that I only get mac address in client list - understandable. Thats why I proposed that a nice enhancement would be being able to pull MAC -> IP arp table from other devices over ssh. For extra flexibility I'd propose that you could enter a regex in setting to be able to parse every arp format available.