net-mgmt/check_nwc_health: Update to 8.0

Changes since 7.12.1.3:

• add some exceptions to hrDeviceDiskStorage and hrDeviceNetwork
• add Vormetric Appliance
• broadcast traffic is now shown as percentage of the overall traffic (...broadcast_in) and percentage of the available bandwitdth (..._broadcast_usage_in).
• errors and discards are now calculated as percentage of all received/sent packets
• TenGig-VRF-MPLS-Dingsbums without errors and discard metrics are no longer treated as StackSubs

Reported by: portscout