Bug 19271: Show vendor name on ordered/spent lists

Bug 19271: Show vendor name on ordered/spent lists

 Improvements to the display of lists of ordered and received orders:
 - Show the vendor's name instead of the internal number

 To test:
 - Make sure you have some pending and received orders
 - Access the Spent and Ordered pages by clicking on the
   amount ordered or spent on the acq start page
   - Verify that
     - Vendor name shows

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>