UC-DPPS-CP-117: Create/update atmospheric density model pool
Summary
Missing UC that has to be factored out of UC-DPPS-CP-112. Point to discus: shall this only contain the availability of the PO-provided reference MDPs or shall it also include DB-related actions? I think, the DB-related part must be abstracted by now (can be specified as extension). Link to UC-DPPS-CP-114 has to be clarified too (#57 (closed))