Fix #96

[PacoDw]

Added:

• The new power_state_mechanism_config attribute was added, and we can use it as a following:

resource "nutanix_virtual_machine" "vm1" {
  name         = "my-vm"
  cluster_uuid = local.cluster1

  num_vcpus_per_socket = 1
  num_sockets          = 1
  memory_size_mib      = 186

  power_state_mechanism_config {
    guest_transition_config {
      should_fail_on_script_failure = true
      enable_script_exec            = true
    }
    mechanism = "ACPI"
  }

}

Also, the following Terraform configuration can work with the old attributes that represented the above new configuration:

resource "nutanix_virtual_machine" "vm1" {
  name         = "my-vm"
  cluster_uuid = local.cluster1

  num_vcpus_per_socket = 1
  num_sockets          = 1
  memory_size_mib      = 186

  should_fail_on_script_failure = true
  enable_script_exec            = true
  power_state_mechanism         = "ACPI"
}

But now they are deprecated, and we don't recomend using them due to inconsistency and bugs that were fixed with this new change.

closes #96