Adds os_cloud_name variable for development_environment role

As part of [1] this adds a new os_cloud_name var for the
development_environment role to be used with the prelaunch vm test
instance creation. This retains current behaviour OS_CLOUD=standalone.
Needed by [2].

https://issues.redhat.com/browse/OSPRH-5754

[1] https://issues.redhat.com/browse/OSPRH-3038
[2] https://review.rdoproject.org/r/c/rdo-jobs/+/52452

tests/roles/development_environment/defaults/main.yaml

@@ -2,3 +2,4 @@ prelaunch_test_instance: true
 prelaunch_test_instance_script: pre_launch.bash
 edpm_privatekey_path: ~/install_yamls/out/edpm/ansibleee-ssh-key-id_rsa
 run_pre_adoption_validation: true
+os_cloud_name: standalone

tests/roles/development_environment/tasks/main.yaml

@@ -6,5 +6,5 @@
     EDPM_PRIVATEKEY_PATH: "{{ edpm_privatekey_path }}"
   ansible.builtin.shell:
     cmd: |
-      alias openstack="ssh -i {{ edpm_privatekey_path }} root@{{ edpm_node_ip }} OS_CLOUD=standalone openstack"
+      alias openstack="ssh -i {{ edpm_privatekey_path }} root@{{ standalone_ip | default(edpm_node_ip) }} OS_CLOUD={{ os_cloud_name }} openstack"
       {{ lookup('ansible.builtin.file', prelaunch_test_instance_script) }}