In a barcode environemtn or a situation with a lot of stock.move.line the subcontract is hard to use with record components because a line is created each time the produce wizard is proccessed. Then each line is duplicate, one with reservation and the other with effective transfer. This commit try to merge them in order to limit the number of lines. Task 2073383 closes odoo/odoo#38689 Signed-off-by: Simon Lejeune (sle) <sle@openerp.com>