Add converters for zipped PrFitted tracks and vertices

Adds a few converters (from → to):

• LHCb::Pr::Fitted::Forward::TracksWithPVs → std::vector<LHCb::Event::v2::Track>
• LHCb::Pr::Fitted::Forward::TracksWithMuonID → std::vector<LHCb::Event::v2::Track>
• LHCb::TrackKernel::TrackCompactVertex backed by LHCb::Pr::Fitted::Forward::TracksWithPVs → std::vector<LHCb::RecVertex> backed by std::vector<LHCb::Event::v1::Track>

These are needed for preparing the HLT1 SelReports in Moore.

Depends on LHCb!2198 (merged) for the .get<T>() accessor on PrFittedTracksWith....