-99 Auto-generate ensemble

[jernsting]

Instead of returning the best hyperparameter configuration one should be able to request an ensemble consisting of the best performing pipeline variants.

[jernsting]

The default behavior of photon can be changed with this method:

photonai_brainhack23/examples/ohbm2023/ensemble_builder.py

Line 5 in c3ca01c

def create_ensemble(copy_pipe_fnc, outer_fold, best_config_outer_fold):