### Summary:
1. Add the MCP dep for python 3.10, since it doesn't support 3.9 and below
2. Create MCPServer, which is the agents SDK representation of an MCP server
3. Create implementations for HTTP-SSE and StdIO servers, directly copying the [MCP SDK example](https://github.com/modelcontextprotocol/python-sdk/blob/main/examples/clients/simple-chatbot/mcp_simple_chatbot/main.py)
4. Add a util to transform MCP tools into Agent SDK tools
Note: I added optional caching support to the servers. That way, if you happen to know a server's tools don't change, you can just cache them.
### Test Plan:
Checks pass. I added tests at the end of the stack.
In particular:
Traceback (most recent call last):
File /Users/alias/Alias/research/openai-agents-python/examples/agent_patterns/litellm.py, line 4, in <module>
from agents import OpenAIChatCompletionsModel,Agent,Runner
File /Users/alias/Alias/research/openai-agents-python/src/agents/__init__.py, line 44, in <module>
from .models.openai_chatcompletions import OpenAIChatCompletionsModel
File /Users/alias/Alias/research/openai-agents-python/src/agents/models/openai_chatcompletions.py, line 57, in <module>
from openai.types.responses.response_usage import InputTokensDetails, OutputTokensDetails
ImportError: cannot import name 'InputTokensDetails' from 'openai.types.responses.response_usage' (/Users/alias/Alias/research/openai-agents-python/env/lib/python3.12/site-packages/openai/types/responses/response_usage.py). Did you mean: 'OutputTokensDetails'?
Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>