Create fields for CPU, Memory, Disk space

[StefanAustin]

Many log sources are tied to a hardware like pFSense, Sophos, Fortigate and have matching logs about hardware utilization.

e.g Sophos for CPU and memory:
vendor_system_use
1.71%
vendor_user_use
3.38%
vendor_free
2194165760
vendor_unit
byte
vendor_used
1424752640

I would like to build a dashboard around these. The system_use could be cpu_used and could be a long (remove the %) so we can use the right dashboard features.