Add original price override to variant-listing

...price line-through

	modified:   app/overrides/add_original_price_to_products_index.rb
	modified:   app/views/spree/shared/_original_price_display.html.erb
	modified:   app/views/spree/shared/_original_price_display_item_added.html.erb
	modified:   app/views/spree/shared/_original_price_display_variant.html.erb