DerivationFrameworkTrainsART: Add new ART tests w/ SharedWriter
In this MR we're replacing the ART tests under DerivationFrameworkTrainsART with four new tests; two running over data18 and the other two running over MC inputs w/ two difference configurations each:
- PHYS + PHYSLITE production in AthenaMP w/ 8 processes + SharedWriter w/ parallel compression
- PHYS + PHYSLITE production in AthenaMP w/ 8 processes + SharedWriter w/o parallel compression (a la Run-2)
This should be a good start and we can certainly add new tests as we go along.