Use getDefaultSession to retrieve an authenticated session

[phochste]

The current authSession is using the deprecated getClientAuthenticationWithDependencies to retrieve the authenticated session for a client.

https://github.com/SolidOS/solid-logic/blob/main/src/authSession/authSession.ts#L6

Using this technique to retrieve a session object will make it hard for external applications, to integrate solid-logic, solid-ui.

It would be better to assume that the application environment could already have created a logged-in session by some external logic. Solid-logic should be able to piggy-back on that external login flow.

Using getDefaultSession could be an integration method.