Options for creating ECAL training datasets for fast simulation

@gcorti @adavis @kreps

This adds an option file that sets up the mc info collector plane for the electromagnetic calorimeter in order to obtain the dataset that can be later used for the training of fast simulation models. I am testing it now locally on 50 events.

Update 17.11.21: the dataset has been correctly produced, statistics summary below

Summary on 50 events

Event 1

Event 2

Event 3