Viewing upcoming joiners/leavers for a package

The content of a package, and by extension agreement (where a package has been added to an agreement line), can change over time. These changes are reflected by the "access start" and "access end" dates on package resources (Package Content Items).

Following the implementation of https://issues.folio.org/browse/ERM-394 the views of packages and package content will show only 'current' titles in a package by default. This story is to allow the user to also select to view titles that will join the package/agreement in the future, or that were previously part of a package/agreement as well as viewing all resources that have ever been in a package/agreement.

Roles and restrictions:
These views are part of the E-resource package preview->E-resources in this package and the Agreement->Agreement lines->E-resources covered by this agreement. They will be accessible to any user who has view permissions for the relevant e-resource or agreement

Workflow / UI expectations:
Applies to lists of PCIs displayed in E-resource package preview->E-resources in this package and Entitlements in the Agreement->Agreement lines->E-resources covered by this agreement
1. A user is shown "Current" titles by default (see ERM-394)
2. A user can select to see "Future", "Dropped" or "All" resources by selecting a filter/button in the UI (see wireframe)
3. After selecting a filter, the user can select the "Export as" option at the top of the E-resource package preview->E-resources in this package and export the list of resources that based on the filter applied at the time

Business rules & constraints:

• The Current filter will display current title (see ERM-394)
• The Future filter will display those resources that have an access start date in the future
• The Dropped filter will display those resources that have an access end date in the past
• The All filter will display all resources irrespective of access start/end date
• The Export as option will respect the selected filter