A response size metric of an upstream service for dynamic badges like [dynamicyaml], (but not [jetbrains]) (#4434)

* Response size metric for all services

* Unused code removed

* Test for service response size metric

* All buckes of the service_response_bytes in a comment

* Register parameter in PrometheusMetrics is optional

* service response size metric enabled for dynamic badges

* Better test name

* JSDoc removed

* One import from one file

* Gather metrics in the background

* Revert saving response time metrics in the background