LP#1357037: add sorting option to Angular line item lists

LP#1357037: add sorting option to Angular line item lists

This applies to the line item lists in the following new
Angular interfaces:

- purchase order
- selection list
- list of line items related to a bib record

The available sort options are:

- line item ID
- title
- author
- publisher
- order identifier (i.e., ISBN, ISSN, and/or UPC)

The method open-ils.acq.lineitem.unified_search is now used to retrieve
line items to make use of existing sorting functionality.

The last sort order used is persistant via a workstation setting

Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>