`kctrl package install` should have an option to configure `spec.cluster`

**Describe the problem/challenge you have**
Today there's no way to configure the `spec.cluster` fields of a PackageInstall using `kctrl`, so if I need to install the contents of my PackageInstall to some other cluster, I would have to do it manually.

**Describe the solution you'd like**
`kctrl package install` should have an option (probably using a flag like `--target`) that can be used to provide the secret name (or kubeconfig, TBD) for the other cluster.

**Anything else you would like to add:**
Slack [thread](https://kubernetes.slack.com/archives/CH8KCCKA5/p1678616452076869).

---
Vote on this request

This is an invitation to the community to vote on issues, to help us prioritize our backlog. Use the "smiley face" up to the right of this comment to vote.

👍 "I would like to see this addressed as soon as possible"
👎 "There are other more important things to focus on right now"

We are also happy to receive and review Pull Requests if you want to help working on this issue.