function isStateEqual(prevState, newState) {
  return (
    prevState.selectedItems === newState.selectedItems &&
    prevState.activeIndex === newState.activeIndex
  )
}
Check if a state is equal for taglist, by comparing active index and selected items.
Used by useSelect and useCombobox.

@param {Object} prevState
@param {Object} newState
@returns {boolean} Wheather the states are deeply equal.