Cutoff overwrite in SGD

[TheEimer]

Currently the user-defined cutoff (which is supposed to be a budget tool) is overwritten with instance specific information in the SGD Bench. I think it would be better to use an additional variable for this and not overwrite the cutoff. This way, users can still use the cutoff (e.g. in some multi-fidelity option?) and the instances can also have different episode lengths.