chore: add movestate and deprecation notice

[azrod]

Description of your changes

If you submit change in the provider code, please make sure to:

• Write or modify examples in examples/ directory
• Write or modify acceptance tests
• Run make generate to ensure the doc was updated properly

How has this code been tested

resource "cloudavenue_vdc_network_isolated" "example" {
  vdc         = cloudavenue_vdc.example2.name
  name        = "rsx-example-isolated-network"
  description = "My isolated Org VDC network"

  gateway       = "192.168.168.254"
  prefix_length = 24

  dns1       = "8.8.8.8"
  dns2       = "8.8.4.4"
  dns_suffix = "example.com"
}

moved {
  from = cloudavenue_network_isolated.example
  to   = cloudavenue_vdc_network_isolated.example
}

cloudavenue_vdc.example2: Refreshing state... [id=urn:vcloud:vdc:xxx]
cloudavenue_vdc_network_isolated.example: Refreshing state... [id=urn:vcloud:network:xxx]
data.cloudavenue_edgegateway.example: Read complete after 4s [id=urn:vcloud:gateway:xxx]

Terraform will perform the following actions:

  # cloudavenue_network_isolated.example has moved to cloudavenue_vdc_network_isolated.example
    resource "cloudavenue_vdc_network_isolated" "example" {
        id                 = "urn:vcloud:network:xxx"
        name               = "rsx-example-isolated-network"
        # (9 unchanged attributes hidden)
    }

Plan: 0 to add, 0 to change, 0 to destroy.

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes


Apply complete! Resources: 0 added, 0 changed, 0 destroyed.