feat(sca): add Image Referencer for Kubernetes, Helm and Kustomize

[gruebel]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

• same as the one for CloudFormation 🙂 was pretty straight forward and will result in a lot more findings compared to Terraform and CloudFormation
• added support for normal Kubernetes manifests
• added support for Helm charts
• added support for Kustomize configs
• I also added code for PodTemplate even it is typically not defined by the user and added a comment to the function

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] I have added tests that prove my feature, policy, or fix is effective and works
• [x] New and existing tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

[schosterbarak]

kustomize too?

[gruebel]

kustomize too?

done