UI: Show available namespaces with RBAC namespace delegation

[CRASH-Tech]

Summary

In the UI I cannot to see available namespaces for my account, and need to enter it.
User may not to know him namespace/s, and will be cool if with empty namespace field will be show resources in all available namespaces, associadet wit that ServiceAccount

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[tu-maurice]

To add to this: It would be helpful to be able to set a default namespace to display using an environment variable, because as far as I can see the web ui tries to display a namespace called "undefined" when argo server is not restricted to a single namespace.

[terrytangyuan]

Could you try the new release https://github.com/argoproj/argo-workflows/releases/tag/v3.4.0-rc1?

A more meaningful default namespace associated with the service account will be displayed instead in this new release.

[basanthjenuhb]

This would be a very nice feature.
But, Its a hard problem,
Reason being, when we use NAMESPACE DELEGATION feature, you are logged in using an account in argo namespace,
But you can perform an operation in any namespace using an account present in that namespace.

To show available namespaces,
I would have to loop over all namespaces, then each account in that namespace, and see if any account can be used.
Not sure how fast would this be

[tu-maurice]

A more meaningful default namespace associated with the service account will be displayed instead in this new release.

That would be the namespace where I installed argo to, right? Not one of the dedicated namespaces I created for workflows to run. Either way I'm having trouble updating to v3.4.0-rc1 so I can't try it out currently, but that's not a topic for this issue.

[agilgur5]

A more meaningful default namespace associated with the service account will be displayed instead in this new release.

For reference, this is referring to #9008

[agilgur5]

Very similar to #9140 / #7405