Collaboration between accounts on tickets

We have added a new optional permission for sub-accounts called "Access to all tickets".

With this permission enabled, sub-accounts can view and reply to all existing tickets, just as the main account could until now, so that different team members, each clearly identified, can work on the same issue or question.

Tickets with more than one collaborator show the users involved in the ticket list itself, and each user is identified in the replies within each ticket.