Add hover text to the gray indicator symbol

It might not be obvious what gray means. Perhaps if it is hovered over, it should say "This message was written by the server"

Edit: By the way, is my other feature request going to be ignored? This post gets approved instantly, but my other post has been lost in "Pending approval" for 5 days. I don't have any other avenues to elevating this to Mojang's attention, so I'm posting here. This feature is make-or-break for us, we won't be enabling chat signing without it.