feat: Auth Testing Strategy Showcase

[sai-sunder-s]

Creating a nox session to run showcase tests. Added a sample test.

Prerequisites:

• Install https://github.com/jgm/pandoc/releases/tag/3.5 and add to path
• Install gapic generator through python3 -m pip install gapic-generator

Steps to test:

• Start the gapic showcase server
• Run python3 -m nox -s showcase

Getting below error even though showcase server is running

E           grpc._channel._InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
E           	status = StatusCode.UNAVAILABLE
E           	details = "failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:7469: Ssl handshake failed (TSI_PROTOCOL_FAILURE): SSL_ERROR_SSL: error:100000f7:SSL routines:OPENSSL_internal:WRONG_VERSION_NUMBER"
E           	debug_error_string = "UNKNOWN:Error received from peer  {grpc_message:"failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:7469: Ssl handshake failed (TSI_PROTOCOL_FAILURE): SSL_ERROR_SSL: error:100000f7:SSL routines:OPENSSL_internal:WRONG_VERSION_NUMBER", grpc_status:14, created_time:"2024-10-09T06:49:16.733288832+00:00"}"
E           >