[FIX] pos_sale: decrease sale.report ID conflict

issues:

- search sale.report with `('order_id', '!=', False)` in list view =>
  you might get lines without sale order, with the wrong product, ...

- group sale.report by product on list view => you might get lines with
  a different product than the group

cause:

the sale.report IDs are an union of sale_order_line.id and
pos_order_line.id => so there can be 2 lines of sale.report with same
IDs but pointing two completely different record.

rejected solution:

using row_number() over() for ID after the UNION ALL => rejected since
there was a `row_number` on sale.report at one point that was removed
because of performance issue (03bd6f5243e189cd05b3fc7ad774cc07ea733e14).

solution:

using negative IDs for pos_order_line lines

drawback:

in 14.0, we already use negative IDs for sale_order without lines =>
the probability of conflict is lower for this case and sale.order.line
not being in conflict is better.

opw-2586062
opw-2694529

closes odoo/odoo#83621

X-original-commit: cdaf046637704b53047b79984669ed2044cd8da6
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/pos_sale/report/sale_report.py

@@ -24,7 +24,7 @@ class SaleReport(models.Model):
 
     def _select_pos(self):
         select_ = """
-            MIN(l.id) AS id,
+            -MIN(l.id) AS id,
             l.product_id AS product_id,
             t.uom_id AS product_uom,
             SUM(l.qty) AS product_uom_qty,

addons/pos_sale/tests/test_pos_sale_report.py

@@ -31,8 +31,8 @@ class TestPoSSaleReport(TestPoSCommon):
 
         session.action_pos_session_closing_control()
 
-        # Orders are reversed, so reports[0] will correspond to the second order
-        reports = self.env['sale.report'].sudo().search([('product_id', '=', self.product0.id)], order='id desc', limit=2)
+        # PoS Orders have negative IDs to avoid conflict, so reports[0] will correspond to the newest order
+        reports = self.env['sale.report'].sudo().search([('product_id', '=', self.product0.id)], order='id', limit=2)
         self.assertEqual(reports[0].weight, 3)
         self.assertEqual(reports[0].volume, 4)
         self.assertEqual(reports[1].weight, 18)