az connectedk8s delete fails as there is no proxy settings params available

- If the issue is to do with Azure CLI 2.0 in-particular, create an issue here at [Azure/azure-cli](https://github.com/Azure/azure-cli/issues)

created with private-preview :

```sh
export REGISTRY= # example: example.registry.com
export REGISTRY_USERNAME=
export REGISTRY_PASSWORD=

bash ./setuptestenv_arck8s.sh

export HTTP_PROXY=:
export HTTPS_PROXY=:
export NO_PROXY=:

az connectedk8s connect -n $azure_arc_ocp_cluster_name -g $poc_rg_name \
--distribution openshift --location francecentral \
--auto-upgrade false --agent-version 0.1.4149-private \
--registry-repository ${REGISTRY} --registry-username ${REGISTRY_USERNAME} --registry-password ${REGISTRY_PASSWORD} \
--proxy-https https://: \
--proxy-http http://: \
--proxy-skip-range , \
--proxy-cert

```

### Extension name (the extension in question)
```sh
az connectedk8s delete
```
has not as much parameters as the
```sh
az connectedk8s create
```

```console
Proxy Arguments
--proxy-cert : Path to the certificate file for proxy.
--proxy-http : Http proxy URL to be used.
--proxy-https : Https proxy URL to be used.
--proxy-skip-range : List of URLs/CIDRs for which proxy should not to be used.
```

### Description of issue (in as much detail as possible)

Env. : OpenShift OCP 4.6 on-prem

```sh
az version
```

```console
{
"azure-cli": "2.28.0",
"azure-cli-core": "2.28.0",
"azure-cli-telemetry": "1.0.6",
"extensions": {
"connectedk8s": "1.3.0",
"k8s-extension": "0.7.1",
"ml": "2.0.1a5"
}
}
```

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