[IMP] web_kanban: provide session user context

* Kanban templates now have access to the object "user_context" which
contains the current uid, lang and timezone

addons/web_kanban/static/src/js/kanban_record.js

@@ -56,6 +56,7 @@ var KanbanRecord = Widget.extend({
             record: this.record,
             widget: this,
             read_only_mode: this.read_only_mode,
+            user_context: session.user_context,
         };
         for (var p in this) {
             if (_.str.startsWith(p, 'kanban_')) {