Add a Data Source to list all VPS

[smortex]

The ovh_dedicated_servers Data Source allows to list all dedicated servers in order to use the ovh_dedicated_server data source to collect their details. The ovh_vps data source is similar to ovh_dedicated_server, but we are missing a component to list all available VPS.

This PR a new data source that return the list of VPS:

data "ovh_vpss" "all_vps" {
}

data "ovh_vps" "vps" {
  for_each = toset(data.ovh_vpss.all_vps.result)
  service_name = each.key
  
}

A better name for this data source is still to be found (There are only two hard things in Computer Science: cache invalidation and naming things).

[scraly]

Hi,
tested and approved :)