Added defaultEqualityCheck to createFacet, and introduced createStaticFacet

[Shenato]

This PR does two things

• Changes the default behaviour for createFacet to not update without doing a defaultEqualityCheck
• Introduces createStaticFacet function to create initial facets outside the react context that are meant to be replaced later by real facet in the react context. Such valid use-case is for example with createContext like so

const myFancyContext = createContext<Facet<number | undefined>>(createStaticFacet(undefined))
export const useMyFancyContext = () => useContext(myFancyContext)

Now your context facet is completely static, not writable and if by accident you manage to observe it won't register any listeners and will give you a warning in production.

[pirelenito]

Amazing job with the unit tests! ❤️👏