Feat/Plot constants for JungFrau

@haufs @ahmedk

New notebook plots calibration constants for JungFrau detectors. It is very similar to already existing notebook for ePix or FastCCD.

A new variable: separate_plot contains a list of parameters, which will be illustrated on separate plots. E.g. if a separate_plot contains the temperature, then calibration constants taken for different temperatures will be shown on different plots.