Add SensorGateway v5 w/Expansion Hub

Device already in LibreNMS, but OID’s changed post firmware update v9.1. Pre 9.1 still had issues reporting with hub. SNMP walk doesn’t show all devices connected.

SensorGateway Web UI:

https://p.libren.ms/view/9532116b
https://p.libren.ms/view/b1823ec0
https://p.libren.ms/view/50b1160f