Refer to unit from variant

variant_unit was moved to variant as part of product refactor.
Old products probably still had a value there, but new ones would have been appearing with nil.

engines/dfc_provider/app/services/affiliate_sales_query.rb

@@ -50,7 +50,7 @@ class AffiliateSalesQuery
       <<~SQL.squish
         spree_products.name AS product_name,
         spree_variants.display_name AS unit_name,
-        spree_products.variant_unit AS unit_type,
+        spree_variants.variant_unit AS unit_type,
         spree_variants.unit_value AS units,
         spree_variants.unit_presentation,
         spree_line_items.price,

engines/dfc_provider/spec/services/affiliate_sales_query_spec.rb

@@ -61,7 +61,6 @@ RSpec.describe AffiliateSalesQuery do
     it "returns data" do
       labelled_row = query.label_row(query.data(order1.distributor).first)
 
-      pending "unit_type"
       expect(labelled_row).to include(
         product_name: "Tomatoes",
         unit_name: "Tomatoes - Roma",