Convert dQ/dx information in both directions for Tracks

[jmcarcell]

needed after key4hep/EDM4hep#311. I think in this case all the comparisons are simply dropped since we are not saving that dE/dx information in another place.

BEGINRELEASENOTES

• Make the conversion handle the fact that EDM4hep tracks do no longer have any dQ/dx information but rather store this in a separate RecDqdx collection.
  • From LCIO to EDM4hep: Create a RecDqdx collection for every converted track collection with the suffix _dQdx
  • From EDM4hep to LCIO: Offer functionality to attach the information stored in RecDqdx collections to converted tracks via the attachDqdxInfo function(s).

ENDRELEASENOTES

[tmadlener]

Thanks. For the full round-trip conversion we will need a bit more logic to attach the RecDqdx and to bring that information back to the Track in LCIO.

[tmadlener]

Added the necessary conversion functionality and updated the tests. This now needs EDM4hep#311 to build (some utilities from there specifically). Hence, these two PRs have to go in simultaneously.