[IMP] test_mail{..mailing/full}: backport tooling improvements

PURPOSE

Purpose of this commit is to backport some improvements done in mail testing
tools done in newer versions. Some of them are required for incoming tests
to be added, other just to try to ease writing tests across versions.

SPECIFICATIONS

Partial backport of odoo/odoo@94208cb8b4

Improve finding outgoing mails and emails when batch methods (mass mailing)
create similar emails, that can be distinguished notably by the subject
in addition to from / to.

Partial backport of odoo/odoo@c98f259736

Add a method to check MailMail, based on a given record. When having duplicates
to differentiate in a given mailing, having just recipients is not sufficient
as multiple emails may match a given recipients list. Checking model / res_id
is another method for finding emails.

Partial backport of odoo/odoo@a3e404e17e

Add some information and values propagation in some custom asserts in mail
test tooling.

Partial backport of odoo/odoo@b915617569

Allow to return <mail.mail> records and found outgoing emails when using
asserts. It eases doing checks in some specific tests e.g. checking
notification layout usage in emails. Indeed this is quite low level and
does not really deserves its own assert tooling methods.

Partial backport of odoo/odoo@bbf4783ac6

Improve checks and asserts done when asserting content of produced
mailing content (mails, traces, ...).

Task-3438381 (TestMail: backport tools)
Prepares Task-2612945 (Mail: Defensive email formatting)

X-original-commit: 2bc28c804a92f206133c352c046dcdd4971fd4a6
Part-of: odoo/odoo#129839

addons/mail/tests/common.py

@@ -324,7 +324,7 @@ class MockEmail(common.BaseCase, MockSmtplibCase):
 
     def _find_sent_email(self, email_from, emails_to, subject=None):
         """ Find an outgoing email based on from / to and optional subject when
-        having conflicts.
+        having a conflict.
 
         :return sent_email: an outgoing email generated during the mock;
         """

addons/mass_mailing/tests/common.py

@@ -121,18 +121,29 @@ class MassMailCase(MailCase, MockLinkTracker):
 
                 # mail.mail specific values to check
                 fields_values = {'mailing_id': mailing}
+                if 'failure_reason' in recipient_info:
+                    fields_values['failure_reason'] = recipient_info['failure_reason']
 
                 # specific for partner: email_formatted is used
                 if partner:
                     if status == 'sent' and sent_unlink:
                         self.assertSentEmail(author, [partner])
                     else:
-                        self.assertMailMail(partner, state_mapping[status], author=author, content=content, fields_values=fields_values)
+                        self.assertMailMail(
+                            partner, state_mapping[status],
+                            author=author, content=content, fields_values=fields_values
+                        )
                 # specific if email is False -> could have troubles finding it if several falsy traces
                 elif not email and status in ('cancel', 'bounce'):
-                    self.assertMailMailWId(recipient_trace.mail_mail_id_int, state_mapping[status], author=author, content=content, fields_values=fields_values)
+                    self.assertMailMailWId(
+                        recipient_trace.mail_mail_id_int, state_mapping[status],
+                        author=author, content=content, fields_values=fields_values
+                    )
                 else:
-                    self.assertMailMailWEmails([email], state_mapping[status], author=author, content=content, fields_values=fields_values)
+                    self.assertMailMailWEmails(
+                        [email], state_mapping[status],
+                        author=author, content=content, fields_values=fields_values
+                    )
 
             if link_info:
                 trace_mail = self._find_mail_mail_wrecord(record)

addons/mass_mailing/tests/test_mailing_internals.py

@@ -15,11 +15,13 @@ from odoo.addons.base.tests.test_ir_cron import CronMixinCase
 from odoo.addons.mass_mailing.tests.common import MassMailCommon
 from odoo.exceptions import ValidationError
 from odoo.sql_db import Cursor
-from odoo.tests.common import users, Form
+from odoo.tests.common import users, Form, tagged
 from odoo.tools import mute_logger
 
 BASE_64_STRING = 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII='
 
+
+@tagged('mass_mailing')
 class TestMassMailValues(MassMailCommon):
 
     @classmethod
@@ -402,6 +404,7 @@ class TestMassMailValues(MassMailCommon):
             msg='The name must be unique')
 
 
+@tagged('mass_mailing')
 class TestMassMailFeatures(MassMailCommon, CronMixinCase):
 
     @classmethod