Bug 34444: Correct handling of sort1 and sort2 values

Bug 34444: Correct handling of sort1 and sort2 values

Removed extraneous sort_1 data elements
Update selectors to use field names for statistics field
Updated code to set the value after finding the correct selector

To test:
* Make sure you have at least 2 funds with different stat settings, using AV and not
* Create a basket with an order line
* Close it and receive shipment
* Create an invoice and receive the order line
* Finish receiving

* Click "Modify fund"
* Switch fund, verify the stat fields are updated accordingly
* Change values for statistical values
* Update fund
* Edit fund again, pull downs are correct
* Change values in form and close, do not update
* Click 'Modify fund' - confrim form is filled with the saved values

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>