Reintroduces the Prometheus metrics wrapper previously available in the
plugins repository, updated for go-micro v5. Exposes request count and
latency histograms for handlers, subscribers, and outgoing client calls
via NewHandlerWrapper, NewSubscriberWrapper, NewCallWrapper and
NewClientWrapper, labelled with service/endpoint/status.
Options cover namespace, subsystem, const labels, histogram buckets and
a custom registerer; duplicate collectors (e.g. from multiple wrappers
sharing the same config) are reused transparently via a cached
metrics bundle.
Fixes#2893
Co-authored-by: Claude <noreply@anthropic.com>
Asim Aslam