mcp: Remove CLI functionality with missing deps (fire, mcp)

[bostrt]

What does this PR do?

Removes what I believe was test code. Alternative fix is to add fire and mcp as project dependencies.

  File "/home/rbost/code/ifd-backend-api/ifd/core/agents/llama_stack.py", line 8, in <module>
    from llama_stack_client import AsyncLlamaStackClient
  File "/home/rbost/code/ifd-backend-api/.venv/lib/python3.13/site-packages/llama_stack_client/__init__.py", line 42, in <module>
    from .lib.agents.agent import Agent
  File "/home/rbost/code/ifd-backend-api/.venv/lib/python3.13/site-packages/llama_stack_client/lib/__init__.py", line 7, in <module>
    from .tools.mcp_oauth import get_oauth_token_for_mcp_server
  File "/home/rbost/code/ifd-backend-api/.venv/lib/python3.13/site-packages/llama_stack_client/lib/tools/mcp_oauth.py", line 13, in <module>
    import fire
ModuleNotFoundError: No module named 'fire'

Test Plan

I have an application using llama-stack-client-python that was failing to launch due to above stack trace. This PR resolves that stack trace by simply removing the code.

[ashwinb]

Thanks. I will make sure this is added back but with correct optional dependencies.