Update QNAP MIB/YAML to display Volumes

Hi. QNAP reports extensive data over SNMP but the current LibreNMS build only references a small amount using what appears to be a generic MIB. There is not a vendor specific QNAP directory in /opt/librenms/mibs. It would be terrific to have more up-to-date data available to monitor, particularly volumes mapped to the different /shares.

I’d be happy to supply the MIB from one of our latest QNAPs that is running ZFS. I’ve successfully integrated it into a Zabbix database on a test bench to verify that the OIDs parse. But I’m woeful at php and am hesitant to pick apart Libre’s code.