JMX Metrics: Static configuration files

[rmfitzpatrick]

From #4 (comment) and similar discussions, a standardized MBean object and attribute specification format should be designed and implemented to allow for JMX Metric Gatherer functionality without the caveats that arise from arbitrary groovy script execution.

At a broad view, these scripts should allow for the configuration of jmx service url, authentication information, and a list of MBeans and their attributes to target otel instruments to be recorded on a configured interval. The implemented support of such files can be via extending the current JMX Metric Gatherer or distributing as a separate utility to disallow groovy script execution in total.

Recommended prior art audit would include jmxtrans and genericJMX

[ItsLastDay]

I shared a high-level proposal about this with Ryan, waiting for feedback.