[DS-1322] Item without Title inaccessible via the UI unless for the admin via ID or Handle

Corresponding JIRA issue: https://jira.duraspace.org/browse/DS-1322

Item without Title inaccessible via the UI unless for the admin via ID or Handle.

This PR adds the ability in JSPUI to display the localized phrase "Undefined" in the item list (browse or search) for items that have no title, so as the user can access the item via the title link.