Use a Cookie object instead of SessionStorage

[sergiodxa]

Change how the Authenticator and Strategy classes work to use a Cookie instead of SessionStorage.

This simplifies many things in the library, since strategies uses a plain cookie to store the intermediate state they may need (like OAuth state and PKCE values), then instead of Remix Auth handling how the user data is stored in the application session, that depends on the app.

Because of that the logout method was removed, all the sessionKey, etc. options were removed, the Strategy failure and success methods were removed and the successRedirect and failureRedirect methods were removed too.

The authenticate method will now return the user data returned by the strategy verify callback, or it will throw. Here it depends on the strategy as it may only throw errors or in case of OAuth2 based strategies it may need to throw a redirect.

This also brings from another important change, as Remix Auth itself only depends on the AppLoadContext and Cookie types from @remix-run/server-runtime, this will help simplify the upgrade to RRv7 and probably also support non-Remix or RR apps.