jet pairing algorithm

• This adds an algorithm to do the pairing, it assumes to get a pt sorted input container from e.g. JetSelectorAlg and returns the pairing of the leading (h1) and subleading (h2) Higgs candidates as four jets in the order:

      // h1_leading_pt_jet
      // h1_subleading_pt_jet
      // h2_leading_pt_jet
      // h2_subleading_pt_jet

• It also fixes a bug in the DiHiggsAnalysis, where the deltaR sorting sorted oppositely which resulted for a wrong pairing in the Resolved analysis.
• makes everything a xAOD::JetContainer instead of IParticleContainer

cfg.addEventAlgo(
            CompFactory.HH4B.JetPairingAlg(
                "JetPairingAlg_" + btag_wp,
                containerInKey="resolvedAnalysisJets_" + btag_wp,
                containerOutKey="pairedResolvedAnalysisJets_" + btag_wp,
                pairingStrategy="minDeltaR",  # so far only minDeltaR
            )
        )

releated to #21 (closed)