feat: support authcode login in `kubectl oidc-login`

[Unix4ever]

Omni now allows using --grant-type=authcode-keyboard option in oidc-login. That allows to log in without forwarding :8000 port from the remote machine. Instead kubelogin will present a link and ask for the one time code.

Clicking the link will open Omni web page with one time code.

Fixes: https://github.com/siderolabs/omni/issues/111

[Unix4ever]

The full flow looks like this

https://github.com/siderolabs/omni/assets/830532/079ae6f7-3902-4e17-9896-565ce4f32a85

[Unix4ever]

/m