Provide access to resource usage for processes and nodes

[Ralph Castain]

Hello all

Operating systems typically maintain a running measure of resource

utilization by active processes. This includes metrics on CPU

utilization, disk accesses, memory size, and network activity.

Define a set of attributes by which these these metrics can be

requested and returned.

Attributes are used as a means of providing for later extension

to include a broader range of metrics.

Replaces https://github.com/pmix/pmix-standard/pull/335, which stalled for several years due to my not having time/energy to address the comments and questions. I believe those have been addressed in the new PR.

The PR is available here: https://github.com/pmix/pmix-standard/pull/521

Please feel free to comment and/or vote your preference

Ralph