Multiple inbox selector

For customers who work with multiple sectors, it's a very common problem that they "lose" the chats because they can't find it between different inboxes.

For agents that work with multiple sectors, they need always being changing between inboxes in order to see if there's a new pending chat.

The same for admins that need to be changing the inbox to review their employee chats.

A possible solution is to give them the possibility to see multiple inbox at the same time, like in the screenshot