Revert "Show picked item as available even if quantity override."

Revert "Show picked item as available even if quantity override."

We don't want this feature. Available quantity shown should be
the quantity available according to priority and should not take
into account overriden picking quantity.
This quantity however needs to be deduced from the available quantity
for other order because even though they have priority , if something
has been picked and sent, they lose the priority de facto.

Showing the "theorical" availability and overrideng order allows the
user to see that it's an override and not an 'due' quantity.

The previous commit is still there in case we change our mind.

This reverts commit 8feb695afa47e4e2fa7aa5477be06551ae522432.