Implement agent_v53.py with agentic frameworks support

[Copilot]

This PR implements the game agent for lesson 53 (Agentic Frameworks) as requested in the TODO comment in the markdown documentation. The new agent_v53.py file demonstrates simple implementations for all three agentic frameworks covered in the lesson:

Frameworks Implemented

1. Semantic Kernel + Agent Framework: Enterprise-ready AI orchestration with kernel functions, plugins, and Azure OpenAI integration
2. Azure AI Agent Service: Platform service for agents with Azure Foundry integration and enterprise security
3. AutoGen: Event-driven, distributed agentic applications with assistant agents

Key Features

• Framework switching capability: Initialize with any of the three frameworks via constructor parameter
• Consistent interface: Maintains the same answer_question() and choose_rps_move() methods as agent_v1.py
• Graceful fallback: Works even when framework libraries are not installed, providing local fallback implementations
• Backward compatibility: Includes GameAgent alias for existing code
• Comprehensive testing: Demonstrates all frameworks with example questions and RPS moves
• Error handling: Robust exception handling with informative error messages

Usage Example

from agent_v53 import GameAgentV53

# Use Semantic Kernel framework
agent_sk = GameAgentV53("semantic_kernel")
answer = await agent_sk.answer_question("What is 15 + 27?")
move = await agent_sk.choose_rps_move()

# Use AutoGen framework  
agent_ag = GameAgentV53("autogen")
answer = await agent_ag.answer_question("What is the capital of France?")

# Use Azure AI Agent Service
agent_azure = GameAgentV53("azure_ai_service")
move = await agent_azure.choose_rps_move()

The implementation follows the exact structure and interface of agent_v1.py while showcasing the different capabilities and use cases of each agentic framework as described in the lesson documentation.

Fixes #62.

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