Also fix shikijika, mebukijika, and genosekuto's alt-form icons, even
though they aren't used anywhere, and fix their cropped sprites.
... Also fix basurao's entries in the pokemon_form_sprites table.
Apparently pokemon_form_sprites isn't for form sprites, but for what
Eevee calls """sprite forms""". So the form names are form names, and
not just for image filenames. So the space versus hyphen matters for
flavour page links.
Every flavor page should work with no missing sprites. Save perhaps for
Unown, because I honestly don't have them.
Every sprite exists as ###-form.png. There is also still a ###.png,
containing a reasonable default form, so people who don't give a crap
about this mess can just use the numbered sprites. Beta forms should
now all be ###-beta.png.
Form groups now have a notion of "in-battle", which is used to hide
overworld sprites when appropriate.
Form sprites have a first-class sense of being a default or not, too.
Deoxys is... well, let's not talk about Deoxys. Deoxys is fixed.