The readers of the two main configuration files for the submission process
have string where an enum is expected. The REST webapp has started to introduce such enumerations it could be better to make their use uniform.
Moreover, the DCInput has a visibility attribute to deal with the "scope" and a readonly flag instead of the more flexible concept of visibility exposed by the REST layer
See also the discussion in this PR: https://github.com/DSpace/DSpace/pull/1852#discussion_r147436850