Allow facets to be used as an initial value of useFacetState

[pirelenito]

The change ensures that we setup an initial subscription to get the value. Currently achieving the same functionality requires additional effects in user-land code.

const anotherFacet = createFacet({ initialValue: 'initial value' })

const ExampleComponent = () => {
  const [facet, setFacet] = useFacetState(anotherFacet)

  return (
    <span>
      <fast-text text={facet} />
    </span>
  )
}

[Bahamoe]

Nice addition