Metric status logger for troubleshooting

[itskarlsson]

During #394 there was an idea of a metrics logger that writes to debug when a threshold of failed requests is reached and gives a list of metrics for troubleshooting. The threshold would be able to be configured in the ecc.yml.

One would also have to change the behavior introduced in #394. When statistics is enabled but not reported, the statistics might write to log but not export it elsewhere instead of being complete disabled.

[manmagic3]

@itskarlsson @masokol can you please elaborate when you say " threshold of failed requests is reached and gives a list of metrics for troubleshooting".