The logout handler registration should be reworked

Presently the logout handler is just a Runnable, the problem with this is if it needs any state it means a lambda or an instance of a class tends to be needed to hold the state e.g.

    private void setupProgramaticLogout(HttpScope sessionScope) {
        logoutHandlerConsumer.accept(() -> {
            sessionScope.setAttachment(AUTHENTICATED_IDENTITY_KEY, null);
        });
    }

It would likely be better for the logout handler to be able to request the scope it needs so maybe pass in the 'org.wildfly.security.http.HttpServerScopes' at the very least.