Add an option to enroll in a crew quad when signing up to a volunteer role

[Planks]

Add an option to enroll in a crew quad when signing up to a volunteer role

This is at no discount but the quads are being reserved for crew first so I need to collect a list of who wants one. I need the user's full real name and email address to give to the hotel for the booking.

These will be standard pay at the hotel rates. Requests are not guaranteed. After the booking is made for crew the rest of the rooms will go up for general sale

Any other Qs reply here I have email pings on github enabled