Handle names/refs/destinations/destination as Arrays

[freenerd]

Moving this discussion out of https://github.com/Project-OSRM/osrm-backend/issues/3304

Right now we are outputting several values for a field in the same way as OSRM, semi-colon separated. It makes sense for downstream users to split these into an array to work better with it. In fact osrm-text-instructions and MapboxDirections.swift are doing this. We should discuss if this would make sense to move to OSRM right away.

This could happen on during the output serialization only (low effort), but might also make sense to do earlier to aid the new name detection (higher effort)