Add Cloud VM Management API

[ddupont808]

This PR implements support for managing Cua Cloud VMs with the Computer SDK via the Cua Cloud API

Changes Included

• Added computer.stop(), computer.start(), and computer.restart()
• Implemented list_vms, stop_vm, and run_vm in the CloudProvider

Example usage:

from computer.providers.cloud.provider import CloudProvider

async def main() -> None:
    provider = CloudProvider(api_key=api_key, verbose=True)
    async with provider:

        # List all VMs
        vms = await provider.list_vms()
        print(f"Found {len(vms)} VM(s)")
        for vm in vms:
            print(
                f"name: {vm['name']}\n",
                f"status: {vm['status']}\n", # pending, running, stopped, terminated, failed
                f"api_url: {vm.get('api_url')}\n",
                f"vnc_url: {vm.get('vnc_url')}\n",
            )

        # # --- Additional operations ---
        # To stop a VM by name:
        name = "m-linux-96lcxd2c2k"
        resp = await provider.stop_vm(name)
        print(
            "stop_vm response:\n",
            f"name: {resp['name']}\n",
            f"status: {resp['status']}\n", # stopping
        )

        # To start a VM by name:
        name = "m-linux-96lcxd2c2k"
        resp = await provider.run_vm(name)
        print(
            "run_vm response:\n",
            f"name: {resp['name']}\n",
            f"status: {resp['status']}\n", # starting
        )

        # To restart a VM by name:
        name = "m-linux-96lcxd2c2k"
        resp = await provider.restart_vm(name)
        print(
            "restart_vm response:\n",
            f"name: {resp['name']}\n",
            f"status: {resp['status']}\n", # restarting
        )

        # # To probe a VM's status via its public hostname (if you know the name):
        name = "m-linux-96lcxd2c2k"
        info = await provider.get_vm(name)
        print("get_vm info:\n", 
            f"name: {info['name']}\n",
            f"status: {info['status']}\n", # running
            f"api_url: {info.get('api_url')}\n",
            f"os_type: {info.get('os_type')}\n",
        )

asyncio.run(main())