Add a callback in solvers for logging purpose + stopping the algo under some conditions

[nhuet]

Currently in some c++ solvers, there is a watchdog argument which is a function to do that.
We will call it callback from now.
If returning None or False, the algo goes on.
Else, the algo early stops.

[nhuet]

This now partially solved thanks to #361 and #362.
The only solvers without callbacks are currently:

• MAHD -> Implement callback for mahd solver #379
• RayRLlib -> Implement callback for ray.RLlib wrapper #380
• do_solver.GPHH: not possible currently with deap library
• PilePolicy: but nothing done during the solve itself
• SimpleGreedy: but nothing done during the solve itself