Verify state for Spotify OAuth

[foleyash]

I would like to add a check for the state variable inside /utils.ts/ for the module handleSpotifyAuth, which instantiates a state variable that should be verified (simple === will do) by the /api/spotify/getToken endpoint. The state should be included in the request URL (req.url) as the search parameter 'state'. This state variable ensures that the request to /api/spotify/getToken coming from the spotify API is a result of the call we make in handleSpotifyAuth, and not some outside entity. I would look into NextJS Cookies to store a cookie for the state variable between Server Components (this is what all /api/*/route.ts files are).