logout method
Log out from this CARP service
Opens a web view to clear cookies and end the session on the Identity Server.
Only use this method if you used authenticate to authenticate.
Implementation
Future<void> logout() async {
assert(_manager != null, 'Manager not configured. Call configure() first.');
if (!_manager!.didInit) {
await initManager();
}
await manager!.logout();
_authEventController.add(AuthEvent.unauthenticated);
_currentUser = null;
}