Really the eye creature is only useful for me as a debugging tool, so this moves it over to a separate debug page.
It also removes the whole concept of randomizing the eye creature, mainly because it ignores all the rules set forth in the normal creature randomizer, so it's not terribly useful.
This simplifies the code for `creature-page.tsx` a bunch and hopefully makes it easier to understand.
This refactors `creature-symbol.tsx` so that it doesn't have to rely on awkwardly introspecting `JSX.Element` instances to do its job. Now all of that mumbo-jumbo, which is only really useful for when we want to manually construct symbols like the eye creature, is encapsulated in `creature-symbol-factory.tsx`.