CPAlgorithms: add new algorithm for V+jets/Vy+jets overlap removal

This is migrated from TopCPToolkit; credits to @lucremer.

Adding a new algorithm ("VGammaOR" in YAML/ConfigFactory notation) to handle the overlap in Monte Carlo between V+jets and Vgamma+jets events. A V+jets event should be kept if the in_vgamma_overlap value is 0, and a Vgamma+jets event should be kept if it is 1 instead. See the documentation of the VGammaORTool.

The default settings of the algorithm and tool are recommended, i.e. looking up automatically the truth record; therefore it is enough to call (in the YAML config file)

VGammaOR: {}