Notification fix (#3939)

* Fix docstring for NotificationMessage class

* Fix for 'refresh' button in notification table

* Simplify API for marking notifications as 'read'

- Simply update the detail serializer
- No requirement for extra API endpoints
- Same updates for news feed entry
- Hide 'read' news on the home page
- Add ability to mark news items as read via table

* Bug fix for build.js

* Fix for part category template

InvenTree/templates/js/translated/build.js

@@ -2679,7 +2679,7 @@ function loadBuildTable(table, options) {
                     treeColumn: 1,
                 });
 
-                table.treegrid('expandAll');
+                $(table).treegrid('expandAll');
             } else if (display_mode == 'calendar') {
 
                 if (!loaded_calendar) {