Re-implement UI reskin with working legacy toggle

Re-implement UI reskin with working legacy toggle; add return to title option to menu

src/ui/party-ui-handler.ts

@@ -13,7 +13,7 @@ import { getGenderColor, getGenderSymbol } from "../data/gender";
 import { StatusEffect } from "../data/status-effect";
 import PokemonIconAnimHandler, { PokemonIconAnimMode } from "./pokemon-icon-anim-handler";
 import { pokemonEvolutions } from "../data/pokemon-evolutions";
-import { addWindow } from "./window";
+import { addWindow } from "./ui-theme";
 import { SpeciesFormChangeItemTrigger } from "../data/pokemon-forms";
 
 const defaultMessage = 'Choose a Pokémon.';