Garnishment — Dissolution of writ — Person of interest identified in garnishee’s answer and served with notice of right to dissolve writ has statutory right to file motion to dissolve writ within 20 days of service of notice, but cannot challenge garnishment by filing affidavit under provisions of section 77.16 — Section 77.16 applies only to individuals not disclosed in garnishee’s answer — Untimely affidavit claiming ownership of funds in bank account stricken