Create CAPI machines under the EKSA's Cluster's namesapce

**What would you like to be added**:
Currently, CAPI machines (k get machines -A) are created under `eksa-system` namespace. I want them to be under the namespace specified in the EKSA Cluster.

For example,

```
apiVersion: anywhere.eks.amazonaws.com/v1alpha1
kind: Cluster
metadata:
name: a-cluster
namespace: cluster-ns
```

In this case, CAPI machines are created uder `cluster-ns` instead of `eksa-system`

**Why is this needed**:

I want to partition the clusters in the long-lived management cluster.

The issue concerns CAPI machines created for an EKSA Cluster and requests that they use the Cluster's namespace instead of eksa-system. No files, tests, or entry points are identified, so first locate the reconciliation path that creates these machines and its namespace-related tests; done means the example Cluster produces machines in cluster-ns.

Written by the indexing model from the issue text.