[FIX][14.0] shopfloor cluster_picking: fix line split

[mmequignon]

At scan_destination_pack when a destination package is scanned without any qty processed (especially when no prefill quantity is enabled), we would end up with a new move line with qty = 0.

Instead, return an error to the user.

[OCA-git-bot]

Hi @simahawk, @sebalix, @guewen, some modules you are maintaining are being modified, check this out!

[github-actions[bot]]

There hasn't been any activity on this pull request in the past 4 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 30 days. If you want this PR to never become stale, please ask a PSC member to apply the "no stale" label.

[mt-software-de]

@jbaudoux could you reopen this one? And merge it, it is only missing the extension of the test. I can do this after this is merged.