Bug 6721 - improve searching in the acquisitions system

Bug 6721 - improve searching in the acquisitions system

This allows a basket to be searched for by name or invoice number from
anywhere in the acquisitions system. It is accessible by clicking on
"orders search", clicking the '[+]' and filling in the basket or invoice
no. fields.

Author:    Srdjan Jankovic <srdjan@catalyst.net.nz>
Author:    Robin Sheat <robin@catalyst.net.nz>
Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>