Improve code quality for useCreateOffer and useAcceptOffer

[antho1404]

          Instead of dealing with 2 useEffect to try to synchronize a state, I think it would be better to have a `useMemo` as we already have all the information.

Maybe something like that (didn't test, just a quick write)

const [signing, setSigning] = useState(false)
  const activeStep = useMemo(() => {
    if (signing) return CreateOfferStep.SIGNATURE
    if (
      approveCurrencyActiveStep === ApproveCurrencyStep.PENDING ||
      approveCollectionActiveStep === ApproveCollectionStep.PENDING
    ) {
      return CreateOfferStep.APPROVAL_PENDING
    }
    if (
      approveCurrencyActiveStep === ApproveCurrencyStep.SIGNATURE ||
      approveCollectionActiveStep === ApproveCollectionStep.SIGNATURE
    ) {
      return CreateOfferStep.APPROVAL_SIGNATURE
    }
    return CreateOfferStep.INITIAL
  }, [signing, approveCurrencyActiveStep, approveCollectionActiveStep])

As "internally" we only need to know if it's initial state or signing state, this could be replaced by an simple boolean state

Similar comment for the rest.

Also, when using a useEffect we need to make sure to have the cleanup function when dealing with states

Originally posted by @antho1404 in #117 (comment)