[#ARCH-151 Implement FileMgmt service for scheduled file deletion ]

adjusted store service to new changes in fileRef
added changes to migration script for mysql
added new project file-mgmt
added new named query for fetching files and filesystems eagerly
accordingly with the respective instances.
updated delete service to only follow jax-rs delete method specification
tested requirement as well as purge for study and series if empty
[#ARCH-144 Constraint SOP instances to be unique]

changed replaced from boolean to enum status