NXCALS-2827 - getDataForSnapshot - fix for a bug
requested to merge NXCALS-2827-Implement-TimeseriesService.getDataForSnapshot-only-timewindow-bugfix into develop
#Merge request template @acc-logging-team - please have a look for approval.
Fixes a copy/paste CALS bug, takes Variables from Group temporarily until the association is done.
Closes NXCALS-2827