No support for components that directly return `null`

If a component directly returns null like this:

export const DataTableColumnDocs: FunctionComponent<
  IDataTableColumn<object>
> = () => {
  return null;
};

Then it won't find any interface to parse. The same behavior can be seen when a component directly returns a prop like so:

export const AuthenticatedBoundary = ({
  children,
  fallback,
}: AuthenticatedBoundaryProps) => {
  const { isLoggedIn } = useAuthentication();

  if (!isLoggedIn) {
    return fallback;
  }

  return children;
};

Locate the component-parsing entry point and existing tests for components whose return value is inspected. Add regression coverage for components returning null and props directly, then verify the parser still extracts their declared interfaces and prop information.