Add support for ddos_protection_plan in vnet sub-module

[jinkang23]

Is your feature request related to a problem?

In our Azure environment, we assign DDoS Network Protection Plan to any Virtual Networks with Azure Public IPs. Since the Hub NGFW Firewall VM Series have a network interface with Public IP associated, we need to be able to set and enable DDoS protection plan in the azurerm_virtual_network resource. Currently configuration is not available in the vnet sub-module.

I would like to see support for optionally specifying the ddos_protection_plan block in the azurerm_virtual_network resource within the vnet sub-module.

Describe the solution you'd like

variable "ddos_protection_plan" {
  type = object({
    id = string 
    enable = bool
  })
  default = null
}


resource "azurerm_virtual_network" "this" {
  count = var.create_virtual_network ? 1 : 0

  ...

  dynamic "ddos_protection_plan" {
    for_each = var.ddos_protection_plan != null ? [1] : []
    content {
      id = ddos_protection_plan.value.id
      enable = ddos_protection_plan.value.enable
    }
  }

  ...

}

Describe alternatives you've considered.

None

Additional context

No response