Add auto/soft refresh on ticket threads view

[quazardous]

Description
Besides CTRL-R, it would be nice to have a soft (ajax) refresh button for the threads list.
Maybe a global toggle to auto refresh any kind of new messages/notification.

Example

• John (manager): Bob, have you processed all your messages ?
• Bob (junior staff member): well yes nothing on my screen boss !
• John (manager): Have you refresh your page ?
• Bob (junior staff member): ...