Support embedded Link in Plaid React web SDK

[tzha-plaid]

• Add <PlaidEmbeddedLink /> to support embedded Link in the React SDK
• Add embedded Link to storybook

This feature is an unreleased experimental feature that can be enabled for customers on a case-by-case basis. Contact your Account Manager to learn more.

Usage:

 const config = {
    token: "link-token-123",
    onSuccess,
    onEvent,
    onExit,
  };

  return (
    <PlaidEmbeddedLink
      {...config}
      style={{
        height: '350px',
        width: '350px',
      }}
    />
  );