Add observables with amplitude corrected by baseline

[JPorron]

Up to this, the PeaksFinderProcess uses the ADC amplitude of the peaks, but does not correct it substracting the baseline. Some changes are made to keep track of the baseline of each signal and substract it to the peak´s amplitude in order to better reconstruct the energy deposited.

Before:

Fig 1: Observables for a given event before the change.

Now, the event is unaltered, but 2 new observables are added ("peaksAmplitudeBaseLineCorrectedADC" and "peaksAmplitudeBaseLineCorrectedADCSum"):

Fig 2: Observables after the change.

These new observables take into account the baseline of each signal, calculated as the PeaksFinderProcess does for other capabilities:

Fig 3: Calculation of the baseline for each signal.

As we can see, the "peaksAmplitudeBaseLineCorrectedADC" substracts the corresponding baseline:
3578-254=3324
3262-250=3012

Also, the "peaksEnergy", that uses the calibration factor, is now calculated with the corrected amplitude.