Make removing the "Sign out" button easier

[simoheinonen]

Short description of what this feature will allow to do:

Make removing the "Sign out" button easier because many authentication methods don't really support logging out (basic, oauth)

Right now you can do something like this:

    public function configureUserMenu(UserInterface $user): UserMenu
    {
        $userMenu = parent::configureUserMenu($user);

        $items = $userMenu->getAsDto()->getItems();

        foreach ($items as $index => $item) {
            if ($item instanceof LogoutMenuItem) {
                unset($items[$index]);
            }
        }

        $userMenu->setMenuItems($items);

        return $userMenu;
    }

Example of how to use this feature

$userMenu->displayLogout(false);