DepositionGeant4: Allow Selection of Geant4 Tracking Verbosity

This allows the user to set geant4_tracking_verbosity in the config file to values larger than 0 in order to redirect logging output from the G4TrackingManager and G4SteppingManager to the log level chose. for G4cout.

This is purely a debugging feature with no impact on the simulation.

How to use:

[Allpix]
log_level = "WARNING"
log_format = "DEFAULT"
number_of_events = 1
detectors_file = "detector.conf"

[GeometryBuilderGeant4]
log_level_g4cout = "INFO"

[DepositionGeant4]
log_level = "INFO"
geant4_tracking_verbosity = 6