Generic/abstract JFR MeterBinder

[shakuzen]

Please describe the feature request.
Provide an abstraction that simplifies and makes a consistent way to provide metrics based on JFR events.

Rationale
There is already VirtualThreadMetrics which is a MeterBinder providing some meters based on JFR events. Expanding on this and customizing this is not easy to do. We may want to add more metrics for JFR events that are added in new versions of Java, related to virtual threads or anything else. We want to avoid duplicating the handling that's currently present in VirtualThreadMetrics and make it easier to customize. It would also make it easy for users to make their own JFR event-based MeterBinder, including for custom JFR events.

Additional context
See #6009 where this came up in trying to add a new meter based on additional JFR events. See also a related (but different) request for a MeterRegistry that produces JFR events: #2273.