Torts — Negligence — Comparative fault — Automobile accident — Alcohol or drug defense — Trial court erroneously applied section 768.36 to completely bar plaintiff’s recovery where, although jury found that plaintiff was more than 50 percent at fault and that his blood alcohol level was 0.08 or higher, jury did not find that plaintiff’s fault was as a result of an alcoholic beverage as required by subsection 2(b) — If a party intends to rely on section 768.36 as a defense, the jury must make all of the statute’s required factual determinations