Add the ability to generate a kustomization.yaml

[basvandenbrink]

As a:
Fabrikate user

I want:
To generate a kustomization.yaml per environment that includes all generated Kubernetes YAML as resources files for that enviroment.

So that:
I can use kubectl apply -k <environment_dir> to apply the resources to the cluster.

kubectl apply -k has support for ordering the Kubernetes resources. This would solve issues like #20.

Describe the solution you'd like:
Implement a -k or --kustomize option for fab generate. If this option is set, fabrikate will generate a kustomization.yaml file for every environment:

# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

# list of Resource Config to be Applied
resources:
- <component_a>.yaml
- <component_b>.yaml
- <component_c>.yaml

Describe alternatives you've considered:
Describing all namespaces as a static component. Then, when executing fab generate, a separate file will be created with the namespaces. Then, I could first do kubectl apply <namespaces_file>.yaml and then do kubectl apply .. However, this would only solve the namespace not ready problem. There could be other ordering problems that kustomize solve and that are not address by this alternative.

Additional context: