[Py] Implement thinking configuration

[AbeJLazaro]

Gemini new versions have this new output called thinking. Also OpenAI has something similar. It has to be also added in the prompts but in a separate space, not as text. https://chat.google.com/room/AAAAcF_p7ts/kK_9yv8J4AE/kK_9yv8J4AE?cls=10