[Feature Request] Allow Mods to mark message as spoiler

Allow administrators to mark a user's message as a spoiler just in case the user is not keen on the currently available mark as spoiler feature. It would allow for server managers to avoid any events of spoiling major events in movies, games, books, etc. for as many* users as possible who may be unaware of the spoilers that are in their messages. (*obviously depending on each server's mod response time and availability)