[MIG] mass_mailing_usability to v14

mass_mailing_usability/models/mailing_mailing.py

@@ -0,0 +1,14 @@
+# Copyright 2023 Akretion France (http://www.akretion.com/)
+# @author: Alexis de Lattre <alexis.delattre@akretion.com>
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+
+from odoo import fields, models
+
+
+class MassMailing(models.Model):
+    _inherit = 'mailing.mailing'
+
+    def action_view_clicked(self):
+        action = super().action_view_clicked()
+        action["view_mode"] = "tree,form"
+        return action