Enable event organizer to push a "no preference" signup into specific bucket

[Quinn-D]

If an event has multiple buckets, and enables the "no preference" option, attendees can be shuffled between the buckets based on signups. After the event has cast, it would be good for the GM to be able to push each of the "no preference" signups into a specific one. (Ie, change their signup selection to be narrower)

I'm aware this is a known issue and may not have a solution.