ISSUE-19867 - Fluent argocd context command

[eugene70]

In Argo-CD CLI, cluster context is managed through argocd context and argocd login commands. However, these context management commands are a bit different from other command systems, so they can be confusing for beginners. So I want to provide rich functionality by providing various subcommands for the argocd context command, such as the argocd app command.
Example:

argocd context list
argocd context delete <context>
argocd context use <context>
argocd context login <context> [<server>]
argocd context login <context> --core
argocd context logout <context>
argocd context # for compatibility = context list
argocd context —delete <server> # for compatibility = context delete
argocd login <server> —name <context> # for compatibility = context login
argocd logout <context> # for compatibility = context logout