Yet another truther

This adds yet another algorithm to decorate info on the parent boson to jets.

I wanted to follow the truth particle all the way from the initial boson to the b-hadron that we typically use to label b-jets. Once we have some derivations where we store the labeling hadron barcode (atlas/athena!60944 (merged)) this will be a bit easier, but for now I'm just using delta-R matching, where each hadron is assigned to the nearest jet (jets with multiple matches take the closest one).

I did a bit of rewriting in the stuff that @viruelas wrote, since I thought we should use a common function where we could. Not sure how this overlaps with @frenner's truth matching so he might want to take a look too.

Still some todos:

• Only allow one parent particle, make one algorithm for each parent (H, S, Z, t, etc).
• See if I can make the interface use xAOD::IParticleContainer rather than xAOD::JetContainer (might as well be a bit more generic)
• Test with W, Z, top as parent particles.
• Make sure data dependencies are registered.
• Only add the final hadron or quark in a decay chain (not both)
• Rename things, if I manage to make it more generic.