Added OpenStack VM deployment job

- Add `deploy_user_defined_vm` job for configurable VM provisioning
- Implement dynamic OpenStack CLI command construction supporting:
  * Image selection by name/UUID via $VM_IMAGE
  * Flavor specification with $VM_FLAVOR
  * Security group array input ($VM_SECURITY_GROUPS)
  * Network/port options ($VM_NETWORK/$VM_PORT)
  * Floating IP association ($VM_FLOATING_IPS)
- Require core variables: VM_IMAGE, VM_FLAVOR, VM_SECURITY_GROUPS, VM_INSTANCE_NAME
- Add pipeline rule trigger via $DEPLOY_VM == "true"