Added new tests for bug fixed (r28418), SaleOrder_getShoppingCartDefaultCurrency, SaleOrder_getShoppingCartDefaultCurrencyCode, SaleOrder_getShoppingCartDefaultCurrencySymbol.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@28423 20353a03-c40f-0410-a6d1-a30d3c3de9de