Refinery Metrics are three different event goroutines instead of a single, aggregated event

[jharley]

Refinery Metric Events are running in three separate go routines (metrics, upstreamMetrics, and peerMetrics) which can lead to instances where a single millisecond has three different metrics events published (each containing their own data along with the dynamic fields).

Ideally, these three different events would get pre-aggregated into a single coherent event.

Originally opened as #293, which was closed after further investigation.

[kentquirk]

#593 unified all the metrics into a single object. I'm hoping this will address this problem appropriately, although it wasn't a consideration in the redesign.