CPAlgorithms: new algorithm to save the b-tagging scores

This is migrated from TopCPToolkit; credits to @dbaronmo.

Adding a new algorithm to save the per-jet overall and per-flavour b-tagging scores. While this information should not be used directly in analysis right now (uncalibrated!), it is useful for a number of studies (especially in FTAG CP). In the future, the b-taggers may also become calibrated fully continuously...

Example YAML config:

Jets:
  - containerName: 'AnaJets'
    jetCollection: 'AntiKt4EMPFlowJets'
    FlavourTagging:
      - btagger: 'DL1dv01'
        btagWP: 'FixedCutBEff_60'
        saveScores: 'All'

FTag experts can save additional floats via saveCustomVariables, e.g.

Jets:
  - containerName: 'AnaJets'
    jetCollection: 'AntiKt4EMPFlowJets'
    FlavourTagging:
      - btagger: 'DL1dv01'
        btagWP: 'FixedCutBEff_60'
        saveCustomVariables:
          - 'DL1dv01_pb'
          - 'DL1dv01_pc'
          - 'DL1dv01_pu'

would do the same thing as saveScores: 'All'.