Improve UX for CLI login by automatically sharing token

[anbraten]

We can improve the CLI authentication by having the CLI start a server on localhost and the dashboard can POST to it with the token instead of requiring the user to copy paste it.

From lagonapp/lagon#682

https://hyper.rs/guides/1/server/hello-world/

[anbraten]

https://github.com/argoproj/argo-cd/blob/6bf276f675bce582d780623c414e7423f99f8e1c/cmd/argocd/commands/login.go#L207