Chats marked as done should be unmarked if client keeps sending messages

[mihok]

Problem description:

Today if you mark a chat as done this archives the chat unless you go to the All section. If a client comes back and continues to talk after the chat has been marked done by the operator it is likely to fall through the cracks and be missed by the operator. Let's fix that

Suggested solution:

When a client sends a message automatically set open: true