I think there's no call sites for these anymore, so now I can start
repurposing these methods for the new API endpoints I'm planning! :3
Now, `SwfAsset#image_url` approximately matches Impress 2020 logic: use
the thumbnail PNG from the manifest if one exists, or the Impress 2020
converter for canvas movies, or the old AWS copy generated by gnash if
necessary, or return nil.
To help with space, I'm just showing the word "Nostalgic" (or "???" if
it's from a series we don't recognize, this is hardcoded by ID), and
trusting that from context it will be obvious that it's the "Nostalgic
Faerie" case or whatever. (Moreover, in both the button and the select
we're omitting the species name, by similar reasoning!)
Note that this _still_ doesn't actually apply the style to the outfit
whatsoever; this is all just local state as we're continuing to play
with UI concepts. Actually applying it is probably next though! (Though
there's a couple more UI things I want to do, like some affordances to
clarify that a Style is applied and that Expression changes won't work.)
