add progress bar duration for initial time measurement and shell spawn time

[blesson3]

I used the suggested format in #416 AT instead of ETA for duration elapsed after the progress bar. Let me know if that should be changed to something else.

closes #416

[sharkdp]

Thank you very much for your contribution!

This seems to break ETA estimation afterwards? If I do hyperfine 'sleep 1', ETA initially goes up (2s, 3s), stays at 3s, then goes down eventually. Correct behavior (on master) would be to count down from 9s (10 is the default number of runs for long commands, the first has been run already).

[sharkdp]

This function has a lot of arguments already. Adding a bool argument further decreases readability at the call sites. I suggest adding a simple enum

enum ProgressBarTemplate {
  ShowDuration,
  ShowETA,
}

and then add a impl ProgressBarTemplate block with a get_template(&self) -> &'static str function.

[sharkdp]

@blesson3 Are you still interested in getting this merged? Otherwise, I'd like to close it.

[sharkdp]

I'm closing this due to inactivity. Please feel free to comment in case it should be re-opened.