[IMP] stock, mrp: computed picking type on stock.move.line

Easier to access and avoid overwrite in function to check picking type
on manufacturing order

closes odoo/odoo#75691

Enterprise-pr: https://github.com/odoo/enterprise/pull/20102


Related: odoo/enterprise#20102
Related: odoo/upgrade#2785
Signed-off-by: Arnold Moyaux <amoyaux@users.noreply.github.com>