[IMP] event: add sequence on event categories

Reorganise the categories of the events sorting them by sequence.
Same behavior as "eCommerce Product categories".

task-1917687

closes odoo/odoo#32010

Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>

addons/event/models/event.py

@@ -22,6 +22,7 @@ except ImportError:
 class EventType(models.Model):
     _name = 'event.type'
     _description = 'Event Category'
+    _order = 'sequence, id'
 
     @api.model
     def _get_default_event_type_mail_ids(self):
@@ -42,6 +43,7 @@ class EventType(models.Model):
         })]
 
     name = fields.Char('Event Category', required=True, translate=True)
+    sequence = fields.Integer()
     # registration
     has_seats_limitation = fields.Boolean(
         'Limited Seats', default=False)

addons/event/views/event_views.xml

@@ -135,6 +135,7 @@
             <field name="model">event.type</field>
             <field name="arch" type="xml">
                 <tree string="Event Category">
+                    <field name="sequence" widget="handle"/>
                     <field name="name"/>
                 </tree>
             </field>