StatsD metrics support for cube_api and cube_refresher_worker instances.

## Description

`cubestore` instances (router + workers) has support for providing StatsD metrics to observe the performance of the application.
Can we implement a similar functionality in the cube api and cube refresher worker instances as well in the cube core flavor (the docker image distributions)?

Many of application performance observability relies on the logs messages and using them to evaluate seems risky, what if the log message change in the future releases?

Wdyt?