Add Sign in With Apple to Web App

The web app currently does not have an authentication option to Sign in with Apple. Here are the following things that need to be done:

[ ] Use Apple's library to add their Sign in with Apple button to the application, if they have one available. This looks like a useful link to start from
[ ] Use lit html to template whether the client id and secret and redirect url are for the production url, songscope.org or for a development URL, like [localhost](localhost] (might not be the case for Apple like it is with google, if it isn't then just mark this step as done)
[ ] Make a route on the backend that handles the sign in oath process, parses the JWT returned by Apple, and then stores that token back on the client's browser so that the browser can then send it in their authorization bearer http requests to protected API routes in the future, they might do it differently this is just going off of what google does
[ ] If possible, add a feature to automatically renew tokens so that users can sign in once and use the app forever without having to keep signing in

timrolsh / Songscope