[Reports] "Bulk co-op packing sheets" merging product quantities of different orders

[audez]

Description

Instead of displaying one line for every product ordered by a customer, the "Bulk co-op packing sheets" report is merging different orders and displaying the corresponding products total.

Expected Behavior

The "Bulk co-op packing sheets" report should display one line for each customer ordered product.

Steps to Reproduce

1. Pass 2 orders of a bulk product (product with the "group by" option activated
2. Open the "Bulk co-op packing sheets" report (admin/reports/bulk_coop)

Animated Gif/Screenshot

I passed the same order with 3 different customers. But the "Bulk co-op packing sheets" report is only showing "Client1" line, with a total sum adding quantities from "Client1", "Client2" and "Client3" 👎

As a comparison, the "Pack by customer" report is showing one line for every customer 👍

Severity

bug-s3: a feature is broken but there is a workaround