Insurance — Homeowners — Appraisal — Trial court departed from essential requirements of law by allowing insureds’ agent/public adjuster to act as their disinterested appraiser — Fiduciary, such as a public adjuster who is in a contractual agent-principal relationship with insureds, cannot be a disinterested appraiser — Allowing public adjuster to act as insureds’ disinterested appraiser is a harm that cannot be remedied on appeal