Optionally display the evaluated totals ranges when `print`ing

[jotaen]

This came up via https://github.com/jotaen/klog/pull/188 by @rkj.

Consider you have a file:

2020-01-01
Workday
    8:37 - 11:59
    12:48 - 15:23
    -15m

If you print that via klog print, it would be informative to see the duration equivalent for these ranges, e.g.:

5h42m  |  2020-01-01
       |   Workday
3h22m  |      8:37 - 11:59
2h35m  |      12:48 - 15:23
 -15m  |      -15m

That behaviour would be optional, and the flag for it could be like --eval-ranges or --with-totals.