[FIX] portal: use user timezone to display hours on portal chatter

Before this commit:
User timezone would be taken into account when displaying message date on
chatter. It would always display the hour in the server format (UTC).

Now, we correctly use the user timezone to format the date being sent by the
server.

This closes #22812

addons/portal/static/src/js/portal_chatter.js

@@ -6,6 +6,7 @@ var ajax = require('web.ajax');
 var core = require('web.core');
 var Widget = require('web.Widget');
 var rpc = require('web.rpc');
+var time = require('web.time');
 
 var qweb = core.qweb;
 var _t = core._t;
@@ -98,7 +99,7 @@ var PortalChatter = Widget.extend({
     preprocessMessages: function(messages){
         _.each(messages, function(m){
             m['author_avatar_url'] = _.str.sprintf('/web/image/%s/%s/author_avatar/50x50', 'mail.message', m.id);
-            m['published_date_str'] = _.str.sprintf(_t('Published on %s'), moment(m.date).format('MMMM Do YYYY, h:mm:ss a'));
+            m['published_date_str'] = _.str.sprintf(_t('Published on %s'), moment(time.str_to_datetime(m.date)).format('MMMM Do YYYY, h:mm:ss a'));
         });
         return messages;
     },