avocado.utils.podman: Add VLLM container support and enhanced lifecycle management

- Add run_vllm_container() method for creating VLLM containers with AIU support
  * Device mapping for /dev/vfio
  * Volume mounting for model directories
  * Environment variables (AIU_PCIE_IDS, VLLM_SPYRE_USE_CB, optional chunk settings)
  * Privileged mode with custom memory/shm settings
  * Port mapping and VLLM-specific arguments

- Add container lifecycle management methods:
  * list_containers(): List all or running containers
  * logs(): Get container logs with follow and tail options
  * inspect(): Get detailed container information
  * remove(): Delete containers with optional force flag
  * stats(): Monitor container resource usage

- Enhance login() method with API key authentication support
  * Add api_key parameter for token-based authentication
  * Auto-use 'iamapikey' username for IBM Cloud registries
  * Maintain backward compatibility with username/password auth

- Add concurrent container management methods (AsyncPodman only):
  * run_multiple_vllm_containers(): Create N containers concurrently with unique AIU IDs
  * start_multiple_containers(): Start multiple containers in parallel
  * stop_multiple_containers(): Stop multiple containers in parallel
  * remove_multiple_containers(): Remove multiple containers in parallel
  * get_multiple_container_logs(): Retrieve logs from multiple containers concurrently

- Add pull() method for downloading container images from registries

All methods implemented in both synchronous (Podman) and asynchronous (AsyncPodman) versions.
Maintains existing code structure and error handling patterns.

- Assisted by AI tools

Signed-off-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>

Author: abdhaleegit