[IMP] mail: display all activity types in columns

In the activity view, all activity types are now displayed in columns,
even if no activity are scheduled yet for some types.

Note that they are ordered based on their sequence from left to right.

Task 1894990

addons/mail/models/mail_activity.py

@@ -509,13 +509,11 @@ class MailActivity(models.Model):
             res_ids = tuple(a['res_id'] for a in grouped_activities)
             res = self.env[res_model].search([('id', 'in', res_ids)])
             grouped_activities = [a for a in grouped_activities if a['res_id'] in res.ids]
-        activity_type_ids = self.env['mail.activity.type']
         res_id_to_deadline = {}
         activity_data = defaultdict(dict)
         for group in grouped_activities:
             res_id = group['res_id']
             activity_type_id = group['activity_type_id'][0]
-            activity_type_ids |= self.env['mail.activity.type'].browse(activity_type_id)  # we will get the name when reading mail_template_ids
             res_id_to_deadline[res_id] = group['date_deadline'] if (res_id not in res_id_to_deadline or group['date_deadline'] < res_id_to_deadline[res_id]) else res_id_to_deadline[res_id]
             state = self._compute_state_from_date(group['date_deadline'], self.user_id.sudo().tz)
             activity_data[res_id][activity_type_id] = {
@@ -525,6 +523,7 @@ class MailActivity(models.Model):
                 'o_closest_deadline': group['date_deadline'],
             }
         activity_type_infos = []
+        activity_type_ids = self.env['mail.activity.type'].search(['|', ('res_model_id.model', '=', res_model), ('res_model_id', '=', False)])
         for elem in sorted(activity_type_ids, key=lambda item: item.sequence):
             mail_template_info = []
             for mail_template_id in elem.mail_template_ids: