[FIX] mrp, sale_mrp: Avoid merging stock move different bom_line_id

Current behavior:
When using a product kit that have a product kit in his BoM some move line where merging when they shouldn't.
Because of this the delivered count wasn't correctly updated in any sale order using this product

Steps to reproduce:
- Create product B to manufacture with a BoM (type Kit) using component A and component B
- Create product A to manufacture with a BoM (type Kit) using product B and component A
- Create a sale order with product A
- Confirm the sale order and validate the delivery
- The delivered count of product A on the sale order stays at 0

opw-2777810

closes odoo/odoo#87000

X-original-commit: 0e648081
Signed-off-by: Tiffany Chang <tic@odoo.com>
Signed-off-by: Engels Robin (roen) <roen@odoo.com>