* Fix incorrect metrics value for cluster commit
* Rewrite metrics logic, don't use registry, write values directly
* Only report REST timings for requests having HTTP 200 response
* Limit metrics reporting of endpoints to whitelist
The whitelist contains a selection of search, recommend and upsert endpoints.
* Add MetricsParam, remove detail level, keep anonymize
* Request metrics in basic API test
* Specify content type for metrics endpoint
* Add OpenAPI test for metrics endpoint, remove from basic API test
This test probes for some strings that must exist in the output
* Add note that metrics endpoint whitelist must be sorted
Luis Cossío