Abstract away navigation from the pre built UI

[rishabhpoddar]

Allows users to define how page navigation should be done, or if at all across our components. This means that we also allow users to embed the entire signipin experience if they want to in a modal and that should not do any redirection during the process, or after.
Specifically, we want to:

• Allow returning null from getRedirectionURL, which does not do any navigation. Keep in mind that if this is done, for the sign in success event, then our component should not constantly try and redirect (cause it's wrapper around a component that redirects if a session exists)
• Add prop to return of getRoutingComponent() which accepts the path (instead of using the global path), so users can control which UI to show.
• Investigate how clerk components work in terms of embedding.
• Allowing users to use their own navigation lib instead of react router dom