Remove `admin` permissions for ArgoCD instance when namespace label is removed

When a namespace is labelled which is recognised by the operator to grant `admin` privileges to the ArgoCD instance is removed, the Operator must remove the privileges as well, i.e remove the following -

• Role and Role Binding created by the operator
• Remove namespace from the list of namespaces defined in the Cluster Secret.

Acceptance Criteria

• Implement the "renmoving" side of the requirements per https://docs.google.com/document/d/1CDm-J8QPItELQv_GIzs1Y89miXNVUh7RZS85PsxYuwg/edit#heading=h.obahgj87nfva
• All the Role/Role Bindings should be removed.
• Cluster Secret must not have the namespace present in the list of namespace
• A user should be able to remove label on the target namespace and the argocd instance cannot create/manage resources on the target namespace due to permission
• Tested upgrade
• Tested and documented upstream (argocd operator)
• unit test added
• e2e tests added