PIM-3530 : fix the object detacher
PIM-3551 : move object detacher to storage utils bundle
Merge pull request #1950 from akeneo/PIM-3551-variant-group-move-detacher

PIM-3551 : move object detacher to storage utils bundle
PIM-3461: Working solution
PIM-3461: add behat scenario
PIM-3461: fix PR comments