[Sandbox] Simulate unpublishing a company's contractor tax statements

Simulate unpublishing all published contractor tax statements for the company for the current tax statement season, returning them to draft. Sandbox-only: in production this endpoint returns a 404.

Contractor tax statements must be enabled for your account. When they are disabled, this endpoint returns a 404. The company must have at least one published contractor tax statement for the season's year. Returns an empty response body on success.