Print time to complete estimates

We now estimate time to complete in gauging if the max read/write rate is high enough to fit within the timeout. Maybe we should print that to the console? For something like delete with two phases it should print each phase appropriately.

I don't know how accurate the timings will be. It's one thing to use extrapolated timings to WARN on things that will obviously take more than the timeout. It's another thing to make good estimates.

No file or test is named. Start by tracing the existing max read/write rate and timeout estimation, then follow the delete operation's two phases. Done means the console reports an estimated completion time for each phase without implying more accuracy than the current warning calculation supports.

Written by the indexing model from the issue text.