Adds filtering options to view missing avatar gourmets.
Filter the missing gourmets list to show items that contribute towards earning one of the gourmet avatars (snow, spooky, health, candy) and toggle between displaying all uneaten gourmets and only uneaten avatar gourmets. Adds borders around candy items in light brown, health items in light green, spooky items in light orange, and snow items in light blue.
