[IMP] calendar, utm: add multi-edit support for some tree views

PURPOSE

Allow multi-edit for calendar event and utm campaigns. Indeed it gives
flexibility to users when they have to edit several records at once.

SPECIFICATION

Enable multi-edit in each of the following views
  * calendar.view_calendar_event_tree
  * utm.utm_campaign_view_tree

Set the fields not editable to be readonly.

LINKS

PR #42786
Task 2078662

Related: odoo/enterprise#7553
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/calendar/views/calendar_views.xml

@@ -65,15 +65,15 @@
         <field name="name">calendar.event.tree</field>
         <field name="model">calendar.event</field>
         <field name="arch" type="xml">
-            <tree string="Meetings" decoration-bf="message_needaction==True">
-                <field name="name" string="Subject"/>
+            <tree string="Meetings" decoration-bf="message_needaction==True" multi_edit="1">
+                <field name="name" string="Subject" readonly="1"/>
                 <field name="allday" invisible="True"/>
                 <field name="start" string="Start Date"/>
                 <field name="stop" string="End Date"/>
-                <field name="partner_ids"/>
+                <field name="partner_ids" readonly="1"/>
                 <field name="location"/>
                 <field name="state" invisible="True"/>
-                <field name="duration" widget="float_time"/>
+                <field name="duration" widget="float_time" readonly="1"/>
                 <field name="message_needaction" invisible="1"/>
             </tree>
         </field>

addons/utm/views/utm_campaign_views.xml

@@ -45,8 +45,8 @@
         <field name="name">utm.campaign.view.tree</field>
         <field name="model">utm.campaign</field>
         <field name="arch" type="xml">
-            <tree string="UTM Campaigns">
-                <field name="name"/>
+            <tree string="UTM Campaigns" multi_edit="1">
+                <field name="name" readonly="1"/>
                 <field name="user_id"/>
                 <field name="stage_id"/>
                 <field name="tag_ids" widget="many2many_tags"/>