[Umbrella] Support three different kinds of workloads in different providers.

[kerthcet]

What would you like to be added:

• Services (with Endpoints, like inference services)

  • Modal support create modal sandbox with url and token returned #44
  • AWS [aws] support creating services in aws #59
  • Runpod [Runpod] Support runpod as another provider for services #61
  • Nebius [Nebius] Support nebius as another provider for services #62

• Sandboxes (agents execution plane, notebook, shell)

  • AWS
  • Modal
  • Runpod

• Jobs (training jobs, fine-tune jobs)

  • AWS
  • Modal
  • Runpod

The artifacts should be linked in subsequent comments.