The server now uses the same approach as the client of treating
cosmetic formes as real formes, as documented in `FORMES.md`.
This eliminates the need for the `.forme` and `.speciesid` properties
of `Pokemon`.
`pokemon.id` has also been removed: useful, since it turns out half
of its uses were bugs that should have used `pokemon.species.id`.
For historical reasons, move property definitions have been very blurry
across `EffectData`. Fortunately, recent refactors have made it
possible to put them all where they're supposed to be.
