argo-workflows: native helm chart support for `managed-namespace`

[Joibel]

Is your feature request related to a problem?

I would like to install a namespaced controller with a different namespace for my workflows to run in, the managed-namespace.

Related helm chart

argo-workflows

Describe the solution you'd like

I would like direct support for the managed-namespace parameter in argo-workflows, so that I get a namespaced controller with a separate managed namespace with appropriate RBAC and minimal thinking on my behalf.

The argo-events helm chart supports this already. Basically implement something similar

Describe alternatives you've considered

Workaround: use extraArgs and have to think about how to do the RBAC split.

Additional context

N/A