There are cases where auto-filling of qty_done of stock move line is not desirable.
e.g. you assign quants manually for some of the moves in a picking and not the others,
in such case you need to go over all the moves in the picking to either remove qty_done
or fill it in to proceed with the validation of the entire moves. Auto-fill behavior is
also troublesome when this function is used in a manufacturing order. i.e. having
qty_done of the component move live messes up the outcome of the production.
