Request: Add “friends only” option to “Spectators can see my cards”

[Qaanol]

Right now, there is an option for "Spectators can see my cards" which can be set to "yes" or "no".

Speaking for myself, if a random person I don't know joins my table, I don't want them looking at my cards. However, I would be fine with people who I have friended being able to see my cards.

Would it be possible to add a choice for "Only allow spectators who are my friends to see my cards"? This could simply be a choice called "friends" in addition to the "yes" and "no" that are currently available for the "Spectators can see my cards" option.