Initial version of the partitioned performance statistics collector

This collector is based on gostats.
It specifically targets the newer partitioned performance statistics endpoints.
This version sepcifically adds a config option to disable normalization of cluster names.

See OneFS Performance Dataset Monitoring and OneFS NFS Performance Resource Monitoring for more details on this new functionality.

To run it: copy it to your machine, unpack, configure your cluster in goppstats.toml and execute it.