No Picture returned for User and Gifts

[steampoweredtaco]

The issue appears to be in most (if not all?) cases we are only getting the thumbnails for the user's associated with the gift event. However, the library is too strict about checking for another size version of the picture, doesn't find it, and makes the event have a null picture value.

The desired outcome is to add members to the User event that can represent all the image size options that maybe return so library users may check for any size/type that might be available.

Ideally we will also have a helper method on the type, such as "GetBestPictureOption()" that will return the largest and common format (such as png > jpeg > webp)... etc