We will remove segments loop soon so we need first to move
Segment definition to rangedloop package.
https://github.com/storj/storj/issues/5237
Change-Id: Ibe6aad316ffb7073cc4de166f1f17b87aac07363
Track duration of all segment loop observers. Factor out functions to
reduce size.
Still need to send the measurements out via monkit.
Part of https://github.com/storj/storj/issues/5223
Change-Id: Iae0260e250f8ea33affed95c6592a1f42df384eb