Internal chats

The ability for messages in the chat to be hidden from the client. Where we have junior bookkeepers working on Uncat they might want to ask queries to a more senior team member it would be great if this could somehow be built in.. We might want to do that for two reasons a- not to disturb the client where we do not need & b- not to make us look silly asking questions that we should not really have to. This would make it much easier for larger bookkeeping bureaus to operate.