Add function in interfaces to get the algorithm description

[cvanaret]

Uno generates a description of the strategy combination like: TR Fletcher-filter restoration inequality-constrained method with exact Hessian and no regularization or LS Waechter-filter restoration primal-dual interior-point method with exact Hessian and primal-dual regularization

I think it would be beneficial to have a function in the interfaces that returns this description, such that the user can see the algorithm that is used.

cc @amontoison