Revert "EZP-21021: Changed Image FieldType legacy file naming"

This reverts commit e85c03b03547e3198dd6f093a3fa40a2490e43af.
EZP-21021: Changed Image FieldType legacy file naming
Merge pull request #641 from ezsystems/fix/EZP-22021-Legacy_images_naming-reboot

Fix: EZP-22021: legacy images naming, rebooted