Need to be able to display times on console in DTIME

[YaqiWang]

Reason

For depletion calculations in reactor analysis, the time step sizes are sometimes in days and the end time can reach few years. Printing time in seconds makes the screen output non-intuitive. It is desired to print times in DTIME format (https://www.gnu.org/software/pspp/manual/html_node/Time-and-Date-Formats.html) if users want.

Design

I propose to add a parameter in Console like time_format that users can change how times and time step sizes look. The default can be in second without the unit. It is noted that Console already had two parameters time_precision and scientific_time to control how times are outputted. Adding a new parameter makes sense to me. It is also desired that Console provides a setter so that applications can change the format programmatically.

Impact

It is not going to have any impact to calculations but rather a new feature that improves the screen outputs.