separate clr scheduling as a module

[fvarno]

Currently we support two types of round to round clr decay in our CentralizedFLAlgorithm, step and cosine (cosine annealing with warm restarts). However, this could be enhanced by letting the user define and pass it to the Algorithm object. In fedsim-cli we can receive the arguments of the lr scheduler as we do for other definitions like DataManager, Algorithm or Model.