Convert a group thread to a direct thread

Thread administrators can now choose Direct thread in the Move thread form.

People who have participated in the thread retain access, including the thread creator, commenters, identified poll voters, and people who reacted. The administrator making the change also retains access. The thread creator and the administrator making the change become thread administrators.

Group members who only viewed the thread do not retain access. Threads containing anonymous polls cannot be converted because selecting participants could reveal who voted.