This is a basic attempt at the Vandagyre logic, but also things like
"Maraquan items released before the Maraquan X was released"!
I also added a new task, `rails items:update_cached_fields`, which needs
to be run after this change, because it affects the value of
`Item#predicted_fully_modeled?`.
Eyeballing the updated search results for `-is:modeled`, this feels
pretty close? I'm guessing it's not perfect (e.g. maybe a pet type we
got modeled late into its existence, or some items that just never did
fit a certain pet), but feels pretty good.
I also know we had the "modeling hints" override in Impress 2020, which
we aren't reading yet. We should probably take that into account here
too!
