Display the code passed to UaaException in UaaException.getMessage()

Make the logging more informative for the developer. Change simply the code from

    public UaaException(Integer statusCode, String error, String errorDescription) {
        super(statusCode, String.format("%s: %s", error, errorDescription));
        this.error = error;
        ...

to

    public UaaException(Integer statusCode, String error, String errorDescription) {
        super(statusCode, String.format("%s: %s [%s]", error, errorDescription, statusCode));
        this.error = error;
        ...

This will avoid painful debugging and work around.

Do the same for the other concrete classes extending AbstractCloudFoundryException aka ClientV2Exception (seems good), Clientv3Exception (seems good), UnknownCloudFoundryException (to fix)

Start with the UaaException constructor shown in the issue, then inspect the other concrete subclasses of AbstractCloudFoundryException, including ClientV2Exception, Clientv3Exception, and UnknownCloudFoundryException. Confirm the exception messages expose the status code consistently, with the already-correct classes serving as references, and verify the resulting behavior with the project's existing tests.