Add python code for iperf3 pod-to-pod test

[alyssa1303]

This pull request introduces significant enhancements to the Kubernetes client module, adds a new PodRoleCommand class for managing Kubernetes pod roles, and includes updates to the iperf3 module documentation for running benchmarks. Key changes focus on improving functionality, modularity, and usability.

Kubernetes Client Enhancements:

• Refactored the KubernetesClient class to include a _setup_clients method for initializing API clients and a set_context method for switching Kubernetes contexts. Added new utility methods such as get_pod_name_and_ip, get_pod_details, get_node_details, and collect_pod_and_node_info to retrieve and manage pod and node information. [1] [2]

• Modified the run_pod_exec_command method to use an empty string ("") as the default value for dest_path and updated logic to handle this change. [1] [2]

New PodRoleCommand Class:

• Introduced the PodRoleCommand class in pod_command.py to manage Kubernetes pods based on roles (e.g., client or server). This includes methods for setting contexts, retrieving pod details, running commands, and validating configurations.

Documentation Updates:

• Added a new section to the iperf3 module README with detailed instructions for validating, executing, and collecting results from iperf3 benchmarks in Kubernetes environments.

Configuration Updates:

• Updated .pylintrc to disable additional pylint checks for "too-many-public-methods" and "too-many-branches," allowing more flexibility in the codebase.

Utility Enhancements:

• Added an import for save_info_to_file in kubernetes_client.py to save pod and node information to files.