feat: Nova compute driver with storage network IP injection

[skrobul]

This PR introduces a custom Nova compute driver that automatically injects storage network configuration into instance config drives when requested.

Key Changes

• New IronicUnderstackDriver: Extends Nova's standard Ironic driver to support storage network injection
• Nautobot integration: Queries Nautobot GraphQL API to retrieve storage interface configurations for bare metal nodes
• Argo Workflows integration: Triggers Ansible playbooks via Argo when storage networks are needed (when user requests a server with storage=wanted property and the project is enabled for UNDERSTACK_SVM).
• Configurable behavior: Added config options to control IP injection and playbook selection as well as credentials for dependencies
• Kubernetes integration: Added RBAC, secrets, and service account tokens for Nova to access Argo and Nautobot

How it works

When an instance has metadata.storage=wanted, the driver:

1. Runs the configured Ansible playbook via Argo Workflows to set up storage networking
2. Queries Nautobot for the node's storage interface details
3. Injects the storage network configuration into the instance's config drive

Below (simplified) diagram shows how the components interact to make this feature work:

sequenceDiagram
  actor User
  participant Nova
  participant Placement
  participant Argo
  participant Ansible

  participant Nautobot
  participant Ironic
  
  activate Nova
  User ->> Nova: create server
  Nova ->>+ Placement: select node
  Placement -->>-Nova: 
  Nova ->>+ Argo: schedule ansible-run
  Argo ->>+ Ansible: populate IPs
  Ansible ->>+ Nautobot: populate IPs for server
  Nautobot <<-->>- Ansible: exchange info
  Ansible -->>- Argo: completed
  Argo -->>- Nova: completed
  Nova ->> Nautobot: retrieve IPs
  Nautobot -->> Nova: 
  Nova ->> Nova: merge IPs into config drive
  Nova ->> Ironic: boot srv with updated configdrive
  Ironic -->> Nova: done
  Nova -->> User: server is ready
  deactivate Nova

Loading

Configuration

Most of the configuration is under [nova_understack] section of the nova-compute-ironic.

• Storage network IP injection feature can be completely disabled via ip_injection_enabled=False
• Ansible playbook name is configurable via ansible_playbook_filename - this can come handy if we decide to cleanup .yml extensions and name them correctly with .yaml.
• Supports both direct API keys and Kubernetes secret-based authentication

Closes https://rackspace.atlassian.net/browse/PUC-1242
Depends on https://github.com/RSS-Engineering/undercloud-deploy/pull/771

Notes for the reviewer

If reviewing commit-by-commit, please start from c1d22b6 as the earlier commit have been reverted in f9cb501. I have purposefully included them in PR so that Ironic custom hardware manager experiment is recorded in history if we ever want to create something similar.
I have at least one idea where this may become useful, so don't want to just throw it out.