Record the time to simulate

[visr]

@rbruijnshkv and @DanielTollenaar both indicated that they would like it if the log file contained the time it took to simulate a model. We can add this, perhaps we can fish this out of the progress logger in the integrator, which is also used for the progress bar on stdout. This wouldn't include latency and model initialization, but that's probably fine. They can use a command line timing command of choice for that. Also they mentioned wanting to read this time programmatically from the log file, which is probably fragile because the log file format is not fixed and meant for humans not computers.

Additionally we could add a column to this file: https://ribasim.org/reference/usage.html#solver-statistics---solver_stats.arrow
Which would be the number of seconds it took to solve that period. Summing the column gives the total duration.

[rbruijnshkv]

Wonderful suggestion to add computation time per period!

[gijsber]

I like the solver stats solution