review and tweak pmlogconf config files

[goodwinos]

Review pmlogconf config files to (a) avoid duplicate metrics being logged, and (b) reference leaf pmns names rather than non-leaves where that is feasible. This may help reduce pmlogger config parsing PDU traffic, which can be problematic over high latency networks, though issue #1433 may mitigate this somewhat.

On a typical install (as reported by Kenj), there appear to be 70-odd metric names duplicated in a default set of 1000+ metric names. So there is scope for a bit of a review and cleanup.

Related BZ#1973833 - [RFE] Improve remote pmlogger over slow network connections