Bug 11755: ensure that SearchOrders returns booksellerid

The SearchOrders routine should return the booksellerid and this
patch adds it.

This fixes several problems:

[1] The link to the vendor on the order receive page breadcrumbs
    was broken.
[2] The tax calculation in finishreceive.pl didn't run.
[3] The item booksellerid field never got updated during
    receipt.

Booksellerid was returned before bug 10723.

Quick test plan:
Go on orderreceive.pl and verify that the vendor link is correct.

Followed test plan. Vendor link is now correct.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>