Rationalise TruthParentDecorator configs
Follow up to !928 (closed) + !938 (merged)
The configs used for electrons, muons and taus being the same, up to the name of the targetContainer
, use some common config methods rather than duplicating them.
The jet configurations are slightly different but bringing them together with the lepton ones to more easily catch the differences
Outputs unchanged (up to #288)
FYI @baer