Saving the kubernetes config is not unique enough

**Describe the Issue:**

When running the command `doctl kubernetes cluster kubeconfig save {cluster-name OR cluster-id}` the context name, cluster name and auth user name are not unique across multiple Digital Ocean accounts or Teams. This causes authentication to be merged over multiple accounts.

For example if I create the same kubernetes cluster in two teams (e.g. demo-cluster) in the same region (e.g. lon1) the same context, cluster and auth name will be created for both clusters, `do-lon1-demo-cluster`.

Kubectl uses the names to identify whether to merge the config or create new entries so in this case they are always merged on top of each other.

**Environment:**
- doctl version: doctl version 1.68.0-release
- OS: Ubuntu 20.04
- Installation method: Installed from source

**Additional Details:**

Maybe adding an additional flag to allow an override to the context name that could also be used for making the cluster and auth names unique may fix the issue?