Handle the case for existing RHDH instance

Get the name of the rhdh namespace where the instance exists
configmaps should be updated with orchestrator plugins
Add Network Policy, ArgoCD and Tekton manifest

References

Network Policy: https://github.com/parodos-dev/orchestrator-helm-operator/blob/43ed4cb3be357201e58d9770acfda2648c18d9b7/helm-charts/orchestrator/templates/network-policies.yaml

Tekton
Pipeline: https://github.com/parodos-dev/orchestrator-helm-operator/blob/43ed4cb3be357201e58d9770acfda2648c18d9b7/helm-charts/orchestrator/templates/tekton-pipeline.yaml

Task: https://github.com/parodos-dev/orchestrator-helm-operator/blob/43ed4cb3be357201e58d9770acfda2648c18d9b7/helm-charts/orchestrator/templates/tekton-tasks.yaml