GNTau update for HLT

This MR fixes a small bug in the TauGNN class, where the m_config object was left uninitialized, resulting in the track and cluster GNN variables going into the same temporary vector during the graph construction. Therefore, any track variable with the same name as a cluster variable used by the network was being overwritten with the cluster's values. This wasn't noticed before because in the Offline TauID, no two variables with the same name were used.

Also, optional monitoring for the TauID scores and transformed scores is added to the TauWPDecorator class, which will be used by the HLT in a following update (moving the score monitoring from the TrigTauRecMerged algorithm, allowing for multiple TauID algorithms, each in different online monitoring subfolders).

Tagging @ntamir.