macOS: add an icon for the top menu bar

[nkaretnikov]

I disable macOS notifications (the ones that appear at the top right corner), sounds, and hide the dock. I want an icon similar to what Telegram has in the top menu, which shows the number of unread messages. For muted chats the circle around the number is grey, red otherwise. IRCCloud could do the same for channel activity and messages directed to you (not just private ones).

[jwheare]

Thanks yes, we're planning to add this.