[React] Avoid Too Many Spinners with React SuspenseList’s tail Prop

tail is a customization prop for SuspenseList. It works in tandem with revealOrder and has three options: undefined, collapsed, and hidden.

These options can be used to configure how fallbacks are displayed.

• undefined: show all fallbacks
• hidden: show no fallbacks
• collapsed: show only the next fallback

Example:

<React.SuspenseList revealOrder="forwards" tail="collapsed">
  <React.Suspense fallback={<div>Fetching Pokemon...</div>}>
    <ErrorBoundary fallback={"Couldn't catch 'em all."}>