Extend TorperfResult to return parsed new PARTIAL* and ERRORCODE fields
The likely result of legacy/trac#29787 (moved) and legacy/trac#26673 (moved) is that we'll have four new fields in .tpf files:
ERRORCODE. This ticket is for extending metrics-lib to parse and return these fields as soon as they're available. I already have a working branch, so I'm grabbing this ticket.