Revert "[#3261] combining model migration and data migration"
Revert "[#3261] combining model migration and data migration"

This reverts commit 97c2b110813813d0fbf81fbb7222fdfcb67a976c.

hydroshare/hydroshare,hydroshare/hydroshare,hydroshare/hydroshare,hydroshare/hydroshare,hydroshare/hydroshare