Add reproductions/adaptations of the Run 2 Hlt2 Jet lines

Add Hlt2 lines that reproduce the Run 2 jet lines (Hlt2Lines/Jets).

The implementation uses the pre-functionalized HltParticleFlow and HltJetBuilder algorithms and defines specialized wrappers for them.

The Run 2 jet lines rely on 2-body combinations that are intermediate products of the Topo lines. These combinations are used as secondary vertexes to tag the jets. In order to reproduce this functionality, the new jet line module contains code to perform its own reconstruction of these 2-body combinations.

The Run 2 2-body Topo combinations include V0s that are reconstructed as Hlt2 standard particles. This branch incorporates !220 (closed) in order to obtain V0s in the new framework.

This branch is a cleaned-up version of the work in the spradlin-Hlt2JetsJetLowPt branch, https://gitlab.cern.ch/lhcb/Moore/tree/spradlin-Hlt2JetsJetLowPt, with a simplified change history. It supercedes the spradlin-Hlt2JetsJetLowPt branch.

This is the product of work begun by @amato and @spradlin at the July Hackathon.