Draft: Jet-associating and dumping neutral V0 xAOD::Vertex objects

Contents of MR

This MR contains code to dump neutral vertices (v0's) produced in the InDetV0Finder. This was tested on small samples produced by Ligang in the new CA-style FTAG1 derivation format.

I introduce five new files, as well as multiple modifications to the configuration, outputs, and tools code, as well as the necessary modifications to the event loop code.

The JetNeutralVertexAssociator currently does a simple check on the compatibility of the reconstructed neutral vertex and a jet, linking the two if all compatibility selections are satisfied. In the future, more complex associations will be attempted (leveraging larger samples) in order to reconstruct semi-inclusive decay chains of charmed mesons.

Note: it seems that the beamSpotWeight config option doesn't work with this sample. Still not sure the cause, but could be due to the sample.