Enabling truth jets in TRUTH derivations

This gets truth jet building working again in truth derivations. The state after this MR is:

-) The correct large-R jets are built and have the required decorations -) The correst small-R jets are build, but they currently lack the desired truth flavor decorations -) As discussed elsewhere, some extra branches exist in truth DAODs made with master, because branch dropping seems to not be working quite right yet -) There are errors coming from CutFlowSvc to do with a mis-match in the number of weights. I'm not quite sure how to solve this one; it looks like CutFlowSvc has moved and been re-worked in master, so I might ask for a little help with this one.

Note that I've disabled most of the jet-related items for derivations running off of AODs. That's because the truth jet building code currently conflicts with what the jet group is running, and it's not yet clear to me how to fix this all. I hope the jet group will clean up a bit in the next few days/weeks, and then we'll be able to harmonize.

@tadej or @lcorpe , if you're able to look at the CutFlowSvc part (or know someone who could), it'd be much appreciated! I think this is going to turn out to be an event weights issue.

@cdelitzs and I discussed the jet bit, so tagging to put this on her radar.

Not sure who to tag about the small-R flavor labels, but Chris might know for jet/MET, which is a start.

If anyone wants to run a derivation:

Reco_tf.py --inputEVNTFile /cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/DerivationFrameworkART/EVNT.17955321._002707.pool.root.1 --outputDAODFile art.pool.root --reductionConf TRUTH3 --maxEvents 100