chore: Add final actions in test context

[christophd]

• Provide the opportunity to add actions in test context that get run at the end of the test
• Enables test actions to dynamically add cleanup actions for instance when auto removing created resources after a test

Used in Knative and Kubernetes test actions to auto remove created resources after the test.

if (isAutoRemoveResources()) {
    context.doFinally(kubernetes().client(getKubernetesClient())
            .secrets()
            .delete(created.getMetadata().getName())
            .inNamespace(getNamespace()));
}