Changes for v3 Tracking sequence

• Adapt PrCloneKiller such that it can also kill clones in with a v3::Tracks reference container.

• Adapt PrCloneKiller such that it can also kill clones in two v3::Tracks containers, to be uses for killing clones of the same track type, e.g. when the pattern recognition reconstructs two long tracks which are made from the same particle. Will be implemented later.

• GhostProbability algorithm for v3::Tracks, using PartialChiSquared, and outputting a LHCb::Event::v3::GhostProbabilities SOACollection. Needs LHCb!3427 (merged) and LHCb!3366 (closed)

• Write algorithm to merge track containers of v3::Tracks

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