Revisit the requirements and suggest improvements the actor path grouping mechanism

[lgajowy]

see: https://github.com/ScalaConsultants/mesmer/pull/635/files#r1129459979

This task is to plan the work for fixing the actor path selection mechanism. The outcome should be GitHub issues that will be done in later versions (0.10.0 and further). If the fixes are easy, we can consider doing them right away, but we have to be cautious here (no need to prolong something that could be split)

[lgajowy]

There's also an alternative direction to explore here: https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/processor/metricstransformprocessor#aggregate-label-values

We could aggregate the path label in the collector. Ofc that would require always using the collector but maybe that's ok. Note, that actor path is not the only "high cardinality attribute" that will need to be aggregated so it might make sense to use a ready-to-use generic transformer rather to have case-specific implementations for that.

[lgajowy]

Postponing that issue until we get actual user feedback on the actor path grouping mechanism.