Support to CIS-1.6 for k3s distribution

[tarihub]

kube-bench is mainly check security benchmark in k8s. In k3s distribution, there are many difference from it, for example, someone in issue k3s-io/k3s#826 needs a validation for k3s distribution.

So I want to develop a k3s cis-1.6 version according to k3s security document

• https://docs.rancher.cn/docs/k3s/security/self-assessment/_index
• https://rancher.com/docs/k3s/latest/en/security/self_assessment/
• https://rancher.com/docs/k3s/latest/en/security/hardening_guide/

Related PR: #1261