Add Event NX to the Donor CS

This is a suggestion to, seasonally, as events occur, include the event NX items (including pets) in the donor shop. These items would be permanent when purchased this way.

What is not part of my suggestion is to, in any way, disincentive use of the normal event NX through ulterior means, e.g. making it more difficult to obtain, or reducing the duration.

The following effects would occur:

• Players could continue gaining event nx the normal way during events, including those who don't want to or can't pay.
• Players who incorporate an element of an event NX into their style can chose to make it a permanent addition without having to worry about event timing and the expiration or if the specific item will be included next year.
• Players wanting a version of the pet that doesn't expire can do so from a slightly broader list each season.
• The server might see a slight influx of donation revenue during events while making the CS seem somewhat less stale.