Add support for CACERT and APIPROXY

The overlay needs to include these parameters:

lcm-k8s: vca_cacert, vca_apiproxy
mon-k8s: vca_cacert

Currently, mon does not use the apiproxy, but we could consider adding the parameter, in case it's used in the future.

The result (osmclient.overlay) should look like this:

```
applications:
  lcm-k8s:
    options:
      vca_user: admin
      vca_password: 92507b6491fb3d2789fcf8d1b489d1b4
      vca_host: 10.65.78.14
      vca_port: 17070
      vca_pubkey: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDHVk4FGo2jnbKTjvViZdSeOdwB+LOJsSOhSraNR+f15b0EFeJP4U/V0DuZXC7iQ2+BLDZRlHSi633FOiYlRde6/JoAlePF9dST0M1maoagXaAGrNf9u6lHcWw5ITw/GsABgVuC9rwyDWUdjkLsc8b9+lsixLsY6j7+b3ZTa5BvMjQincqCgvCm5OMZs8LvVbsj7Z5yPu0TWJ33YVNMUwnXa1h1E4lGEEs06e1YozR1boBfVKLY91KuY4X07F4zV6o2ojDd3kgcZwlWEhhCzRl0H11IPJrycp0OWCzOmhVCdCIIHlL/E62JeCydDmd9oV4RWXQ0Av3jIqPDx5bTnpI7 juju-client-key"
      vca_apiproxy: 10.28.55.41
      vca_cacert: "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"
  mon-k8s:
    options:
      vca_user: admin
      vca_password: 92507b6491fb3d2789fcf8d1b489d1b4
      vca_host: 10.65.78.14
      vca_cacert: "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"
```

vca_cacert is the result from the command `juju controllers --format json | jq -r '.controllers["osm-lxd"]["ca-cert"]' | base64 | tr -d \\n`

vca_apiproxy is the DEFAULT_IP:
```
DEFAULT_IF=`route -n |awk '$1~/^0.0.0.0/ {print $8}'`
DEFAULT_IP=`ip -o -4 a |grep ${DEFAULT_IF}|awk '{split($4,a,"/"); print a[1]}'`
```