Add more Statistics (like peak depth) in Choco-Solver FlatZinc Frontend

[Hedieh-Haddad]

Hello,

I am using the Choco-Solver with the FlatZinc frontend (fzn-choco) and I noticed that the peak depth is not included in the printed statistics after solving a problem.

I understand that the peak depth can be retrieved programmatically using solver.getMaxDepth(), but it would be very helpful if this information could also be included in the statistics printed by the FlatZinc frontend.

Looking forward to see your response.