[16.0] [FIX] stock_picking_report_valued_sale_mrp: fix components per kit computation when redelivering

[rrebollo]

Fixes #451

This PR contains two commits:

1. Adds a test that reproduces the issue.
2. Introduces a proposed fix for the issue.

🧩 Context

The problem occurs in the following workflow:

1. Sell a kit.
2. Confirm the Sales Order (SO).
3. Validate the related picking.
4. Return the picking.
5. Cancel the SO.
6. Set the SO back to draft.
7. Confirm the SO again.

At this point, the system generate another picking and you validate this too, and we noticed that the kit component quantities shown on the delivery slip report were incorrect.

🔍 Root Cause

The issue appears to stem from the calculation of the component quantities per kit during this sequence of operations.

🛠️ Proposed Fix

This PR provides an initial attempt to resolve the incorrect quantity computation. Additional details and discussion can be found in the linked issue.

HT14789
@BinhexTeam

[OCA-git-bot]

Hi @chienandalu,
some modules you are maintaining are being modified, check this out!