Add infrastructure to output topocluster calibration hit decoration.

In samples with calibration hits we need to add an extra decoration to CaloCalTopoClusters which uses the calibration hits as the basis for the calculation. This needs to be added to the aux item list inside the topocluster config. It is apparently not possible to modify this list later on in outside configuration code. Since we don't need this in default workflows this is put under the control of a python flag. The name of the decoration is defined via as second flag to allow it to be updated consistently in one place. This is disabled by default because most workflows do not contain calibration hits.