[FIX] base_comment_template: Consider multi-company and partners

In a multi-company context, if you put a template with company_id set,
this template is trying to be assigned to any document, no matter which
company it belongs, as it runs in a sudo environment, or at least, you
can have several companies seen at the same time.

We add the company discriminant for avoiding this problem.

Furthermore, the previous code was adding a domain where the right
part may be `False` with the operator `in`, provoking an unexpected
behavior in the search.

This has been fixed stating directly the expected domain.

TT42591

base_comment_template/tests/test_base_comment_template.py

@@ -1,5 +1,6 @@
 # Copyright 2020 NextERP Romania SRL
 # Copyright 2021 Tecnativa - Víctor Martínez
+# Copyright 2023 Tecnativa - Pedro M. Baeza
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 from odoo.tests import common
 from odoo.tools.misc import mute_logger
@@ -18,14 +19,12 @@ class TestCommentTemplate(common.SavepointCase):
         cls.partner_id = cls.env.ref("base.res_partner_12")
         cls.partner2_id = cls.env.ref("base.res_partner_10")
         cls.ResPartnerTitle = cls.env["res.partner.title"]
-        cls.main_company = cls.env.ref("base.main_company")
-        cls.company = cls.env["res.company"].create({"name": "Test company"})
         cls.before_template_id = cls.env["base.comment.template"].create(
             {
                 "name": "Top template",
                 "text": "Text before lines",
                 "model_ids": [(6, 0, cls.user_obj.ids)],
-                "company_id": cls.company.id,
+                "company_id": False,
             }
         )
         cls.after_template_id = cls.env["base.comment.template"].create(
@@ -34,13 +33,9 @@ class TestCommentTemplate(common.SavepointCase):
                 "position": "after_lines",
                 "text": "Text after lines",
                 "model_ids": [(6, 0, cls.user_obj.ids)],
-                "company_id": cls.company.id,
+                "company_id": False,
             }
         )
-        cls.user.partner_id.base_comment_template_ids = [
-            (4, cls.before_template_id.id),
-            (4, cls.after_template_id.id),
-        ]
 
     @classmethod
     def tearDownClass(cls):