Function ensure_headers_allowed 

pub fn ensure_headers_allowed(
    origin: Option<&str>,
    referer: Option<&str>,
    sec_fetch_site: Option<&str>,
    request_origin: &str,
    public_site_origins: &[String],
    mode: RequestSourceMode,
) -> Result<()>

Validates raw source header values against the request and public-site origins.