Show target cluster in the list of apps.

**Describe the problem/challenge you have**
The list of apps are not showing any info about target clusters.

**Describe the solution you'd like**
I would like to execute `kubect get Apps` and get output something like:
```
➜ kubectl get Apps
NAME DESCRIPTION SINCE-DEPLOY AGE CLUSTER
nginx-app Reconcile succeeded 22s 48m myClusterFoo
simple-app Reconcile succeeded 31s 72m local
new-app Reconcile succeeded 21s 32m local
```

where `local` means my management cluster, the one on which I'm executing `kubectl` or `kapp`. And `myClusterFoo ` is a string from: `app.spec.cluster.kubeconfigSecretRef`, with CAPI it's one of my workload cluster.

Example of my App:

```
apiVersion: kappctrl.k14s.io/v1alpha1
kind: App
metadata:
name: nginx-app
namespace: default
spec:
cluster:
kubeconfigSecretRef:
name: myClusterFoo-cluster-kubeconfig
namespace: default

fetch:
- http:
url: https://raw.githubusercontent.com/kubernetes/website/main/content/en/examples/application/deployment.yaml
template:
- ytt: {}
deploy:
- kapp: {}
```

**Anything else you would like to add:**
I'm happy to prepare PR for it :-)

---
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.

Start by locating the implementation and tests for `kubectl get Apps` output in kapp-controller, then trace how `app.spec.cluster.kubeconfigSecretRef` is represented. Done means the list includes a CLUSTER column, showing the referenced workload cluster or `local` for the management cluster, as in the issue's example.

Written by the indexing model from the issue text.