Move to kubebuilder v2 generated project

[barney-s]

Re-generated scaffolding and merged existing controller files into it

kubebuilder init --domain apache.org kubebuilder create api --group airflow --version v1alpha1 --kind AirflowBase --controller --resource --namespace=true kubebuilder create api --group airflow --version v1alpha1 --kind AirflowCluster --controller --resource --namespace=true