feat: refining resource exclusion logic based on built-in or custom ownership

[thapabishwa]

Description

This pull request centers around an enhancement to the exclusion logic based on resource ownership. If the resource is owned by built-in workloads then the resource should be excluded.

This change ensures that resources owned by custom owners(Like CRDs) are not mistakenly excluded, while ensuring that resources owned by built-in workloads are excluded.

For example, consider the scenario where there are two pods: one named my-pod, which doesn't have any owners, and another named pod-with-crd-owner, which is created and managed by a custom owner(acid.postgres.com/v1/postgresql), and other regular pods owned by built-in workload kinds.

kubectl get pods -o custom-columns="NAME:.metadata.name,OWNER:.metadata.ownerReferences[*].kind"
NAME                                  OWNER
my-pod                                <none>
aws-for-fluent-bit-m46xg              DaemonSet
coredns-655c69d4f4-fg82d              ReplicaSet
coredns-655c69d4f4-kmx6c              ReplicaSet
ebs-csi-controller-846b7ddddb-nj6ks   ReplicaSet
ebs-csi-controller-846b7ddddb-tbl88   ReplicaSet
pod-with-crd-owner                    acid.postgres.com/v1

Before

Since we currently do not verify whether the owner of the resource is a built-in workload, pod with custom owner is not listed when calling ListArtifact function as per PR #214.

go run example/trivy.go
Name: my-pod, Kind: Pod, Namespace: default, Images: [nginx:latest]

After

Once we start validating the resource's owner, the pod with custom owner becomes visible in the listing when calling ListArtifact function.

go run example/trivy.go
Name: my-pod, Kind: Pod, Namespace: default, Images: [nginx:latest]
Name: pod-with-crd-owner, Kind: Pod, Namespace: kube-system, Images: [nginx:latest]

[chen-keinan]

lgtm 🚀