Fix UserData not being found when added to a project

[bddvlpr]

Description

When a user data resource is nested in a particular project using project_id, a global search will not find that particular user data.

If for some reason (as the case before),the userdata list command succeeds but doesn't contain any user data itself, throw an error for that.

Reproduce bug

resource "cloudstack_project" "test-project" {
  name = "test-project"
}

resource "cloudstack_user_data" "test-userdata" {
  name = "cloudinit-test"
  userdata = base64encode(file("../some-cloudinit.yaml"))
  project_id = cloudstack_project.test-project.id
}