Fix the fill number in the "per fill" histograms

[venturia]

The list of sources of the fill number should be reviewed. There should be a way to get the fill number event by event. In this case I have to add a method to update the fill number event by event in the RunHistogramManager class. I have to prepare the code not to use the information if it is not valid and use the previous source. Very likely I will first check the information per run and then per event. In case of inconsistency I have to define which has the priority and in case of invalid information I have to use the valid one.
The pieces of code which use RunHistogramManager to fill "per fill" histograms will have to be modified to update the fill number event by event
Finally the impact on the timing has to be checked