Add total merges and refreshes in summary output #614
Description
Currently our summary output includes sections like:
| All | Total refresh time | | 131.531 | min |
| All | Min refresh time per shard | | 43.0791 | min |
| All | Median refresh time per shard | | 44.0437 | min |
| All | Max refresh time per shard | | 44.4079 | min |
i.e. only times not count.
Given #608 we can't rely too much on node-stats atm, so makes sense to also present the Total refreshes / Total merges (maybe an avg rate too based on total time?)