Support IAzurePrivateEndpointTarget on AzureKustoClusterResource

AzureKustoClusterResource doesn't implement IAzurePrivateEndpointTarget.

According to https://learn.microsoft.com/en-us/azure/private-link/private-endpoint-dns, Kusto Clusters need:

```
privatelink.{regionName}.kusto.windows.net
```

for a Private DNS zone name.

That `regionName` is a problem since we've only used hard-coded strings before.

We should figure out how to support private endpoints on Azure Kusto.