“Whether the Act of 1984, Pub. L. 98-620, title IV, § 414(a), Nov. 8, 1984, 98 Stat. 3335, 3362, amending the language in 35 U.S.C. § 144 to provide that this Court shall issue ‘its mandate and opinion’ instead of ‘a certificate of its proceedings and decision,’ requires this Court to issue an opinion, precluding Rule 36 affirmances without opinion, when reviewing appeals from the United States Patent and Trademark Office.”