Kubernetes Cluster resource missing externalloadbalanceripaddress and enablecsi parameters

## Problem
The `cloudstack_kubernetes_cluster` resource is missing several parameters that are available in the CloudStack UI and API when creating Kubernetes clusters.

### Missing Parameters

1. **`externalloadbalanceripaddress`** - Required for HA clusters (multiple control nodes) on Shared networks
- Available in the UI when HA is enabled
- Required to specify the external load balancer IP for API server access across control nodes
- Without this, HA clusters on Shared networks cannot be created via Terraform

2. **`enablecsi`** - Enable CloudStack CSI (Container Storage Interface)
- Available in the UI and API
- Cannot enable CSI via Terraform

### Impact
- HA Kubernetes clusters on Shared networks cannot be deployed via Terraform
- CSI cannot be enabled for clusters created via Terraform
- Users must manually configure these settings in the UI after Terraform deployment

### Environment
- CloudStack: 4.22.0.0
- terraform-provider-cloudstack: latest

### Expected Behavior
The resource should support all parameters available in the CloudStack API:
```hcl
resource "cloudstack_kubernetes_cluster" "example" {
name = "my-cluster"
zone = "zone1"
kubernetes_version = "1.33.1"
service_offering = "Medium Instance"
size = 3
control_nodes_size = 3 # HA cluster

# These should be available but aren't:
externalloadbalanceripaddress = "10.0.0.100" # Missing
enablecsi = true # Missing
}