Enable users to add/delete allowed source namespaces to/from AppProject via CLI

Epic Goal

• add the below sub commands to ArgoCD CLI
  • argocd proj add-source-namespaces
  • argocd proj delete-source-namespaces

Upstream ticket: https://github.com/argoproj/argo-cd/issues/16189

Why is this important?

• Users must be able to whitelist one or many namespaces for app creation via the CLI
• Users must be able to blacklist one or many namespaces for app creation via the CLI

Scenarios

Adminstrative user of ArgoCD wants to whitelist/blacklist a tenant namespace to allow tenants to be able to create Argo Applications in their respective tenant namespaces. This has to be done via the AppProject by adding or removing the namespaces AppProject.Spec.SourceNamespaces. It would be preferable to do it via the CLI and the WebUI rather than users editing the source namespaces vi oc or kubectl client.

Acceptance Criteria (Mandatory)

• CI - MUST be running successfully with tests automated
• Release Technical Enablement - Provide necessary release enablement details and documents.
• CLI documentation is updated.

Dependencies (internal and external)

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Previous Work (Optional):

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Open questions::

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Done Checklist

• Acceptance criteria are met
• Non-functional properties of the Feature have been validated (such as performance, resource, UX, security or privacy aspects)
• User Journey automation is delivered
• Support and SRE teams are provided with enough skills to support the feature in production environment