feat: allowedLabels and allowedAnnotations #1501
Description
Describe the feature
Instead of forbidding a long list of labels/annotations, which will never be exhaustive, there should be an allow-list feature. According to the Kubernetes docs labels/annotations without a prefix are always custom user labels, so those should always be allowed. Additionally with Regex it would be possible to allow all labels that belong to a certain prefix.
Expected behavior
Only specific labels are allowed to be added to the namespace.