[IMP] mail: use _notify_get_action_link and not inline string

Note that this also add data-oe-model and data-oe-id in XML.
This allow us to avoid to load these links as external URL when
a user receive it in inbox instead of external mail client.
See file addons/mail/static/src/js/thread_widget.js -> _onClickRedirect

Task ID: 1895451

closes odoo/odoo#39958

Related: odoo/enterprise#6414
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>

addons/mail/data/mail_data.xml

@@ -308,7 +308,7 @@
     <span style="margin-top: 8px;">You have been assigned to the <t t-esc="model_description or 'document'"/> <t t-esc="object.display_name"/>.</span>
 </p>
 <p style="margin-top: 24px; margin-bottom: 16px;">
-    <a t-att-href="'/mail/view?model=%s&amp;res_id=%s' % (object._name, object.id)" style="background-color:#875A7B; padding: 10px; text-decoration: none; color: #fff; border-radius: 5px;">
+    <a t-att-href="access_link" t-att-data-oe-model="object._name" t-att-data-oe-id="object.id" style="background-color:#875A7B; padding: 10px; text-decoration: none; color: #fff; border-radius: 5px;">
             View <t t-esc="model_description or 'document'"/>
     </a>
 </p>
@@ -341,7 +341,7 @@
     on <span t-field="activity.res_name"/>
     to close for <span t-field="activity.date_deadline"/>.<br />
     <p style="margin: 16px 0px 16px 0px;">
-        <a t-att-href="'/mail/view?model=%s&amp;res_id=%s' % (activity.res_model, activity.res_id)"
+        <a t-att-href="access_link" t-att-data-oe-model="activity.res_model" t-att-data-oe-id="activity.res_id"
             style="background-color:#875A7B; padding: 8px 16px 8px 16px; text-decoration: none; color: #fff; border-radius: 5px;">
             View <t t-esc="model_description or 'document'"/>
         </a>

addons/mail/models/mail_activity.py

@@ -387,7 +387,11 @@ class MailActivity(models.Model):
         for activity in self:
             model_description = self.env['ir.model']._get(activity.res_model).display_name
             body = body_template.render(
-                dict(activity=activity, model_description=model_description),
+                dict(
+                    activity=activity,
+                    model_description=model_description,
+                    access_link=self.env['mail.thread']._notify_get_action_link('view', model=activity.res_model, res_id=activity.res_id),
+                ),
                 engine='ir.qweb',
                 minimal_qcontext=True
             )

addons/mail/models/mail_thread.py

@@ -2812,6 +2812,7 @@ class MailThread(models.AbstractModel):
             values = {
                 'object': record,
                 'model_description': model_description,
+                'access_link': self._notify_get_action_link('view'),
             }
             assignation_msg = view.render(values, engine='ir.qweb', minimal_qcontext=True)
             assignation_msg = self.env['mail.thread']._replace_local_links(assignation_msg)