Fix: Conditional roles

[x42en]

This pull request introduces updates to the python_a2a library to improve flexibility and compatibility in handling function roles and API keys for OpenAI and Ollama integrations. The changes primarily focus on adding configurable function roles and API key support, ensuring better customization and adaptability for different use cases.

Enhancements to API Key Handling:

• python_a2a/client/llm/ollama.py: Made the api_key parameter configurable instead of hardcoding it to "ollama" in both client and async_client initialization. [1] [2]
• python_a2a/server/llm/ollama.py: Similarly updated the api_key parameter to be configurable for client and async_client. [1] [2]

Improvements to Function Role Configuration:

• python_a2a/client/llm/openai.py: Introduced the function_role attribute with a default value of "function" and replaced hardcoded function roles in methods such as send_message and send_conversation. [1] [2] [3] [4]
• python_a2a/server/llm/openai.py: Added the function_role attribute and updated function role handling in methods like handle_message and handle_conversation. [1] [2] [3] [4]
• python_a2a/client/llm/ollama.py and python_a2a/server/llm/ollama.py: Set function_role to "tool" for Ollama-specific integrations. [1] [2]

Associations

This PR should /close issue #53