[FIX] sale: do create of sale.order.line in batch

With this patch, `sale.order.line` records can now be created in batch,
this means that operations such as:

    - SO copy
    - SO create + commands
    - SO import

will benefit from this patch in terms of performance.

E.g.

For a SO of 2k lines, duplicating the SO takes:
Before patch: 1515s
After patch: 171s

Creating an SO with SOL as o2m commands:
Before patch: 181s
After patch: 43s

closes odoo/odoo#32040

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

1 files changed, 17 insertions, 14 deletions

diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index c73944cd777..6c698a35169 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -1046,20 +1046,23 @@ class SaleOrderLine(models.Model):
                     res[field] = line._fields[field].convert_to_write(line[field], line)
         return res
 
-    @api.model
-    def create(self, values):
-        if values.get('display_type', self.default_get(['display_type'])['display_type']):
-            values.update(product_id=False, price_unit=0, product_uom_qty=0, product_uom=False, customer_lead=0)
-
-        values.update(self._prepare_add_missing_fields(values))
-        line = super(SaleOrderLine, self).create(values)
-        if line.product_id and line.order_id.state == 'sale':
-            msg = _("Extra line with %s ") % (line.product_id.display_name,)
-            line.order_id.message_post(body=msg)
-            # create an analytic account if at least an expense product
-            if line.product_id.expense_policy not in [False, 'no'] and not self.order_id.analytic_account_id:
-                self.order_id._create_analytic_account()
-        return line
+    @api.model_create_multi
+    def create(self, vals_list):
+        for values in vals_list:
+            if values.get('display_type', self.default_get(['display_type'])['display_type']):
+                values.update(product_id=False, price_unit=0, product_uom_qty=0, product_uom=False, customer_lead=0)
+
+            values.update(self._prepare_add_missing_fields(values))
+
+        lines = super().create(vals_list)
+        for line in lines:
+            if line.product_id and line.order_id.state == 'sale':
+                msg = _("Extra line with %s ") % (line.product_id.display_name,)
+                line.order_id.message_post(body=msg)
+                # create an analytic account if at least an expense product
+                if line.product_id.expense_policy not in [False, 'no'] and not line.order_id.analytic_account_id:
+                    line.order_id._create_analytic_account()
+        return lines
 
     _sql_constraints = [
         ('accountable_required_fields',