chore: Add tool usage + session audio recording

[Ruthvik-1411]

Changelog:

1. Handling tool calls is added for gemini live events.
2. A decorator was built to convert any function tool to openapi specified declaration schema. This abstracts the developer from creating the entire function description again. They can just write the function very cleanly.
3. Minor changes in the UI to display tool call events in the transcript.
4. Added support for session audio recordings. Now, all the user and audio speech is recorded and saved after the session ends.

Todo:

1. Abstract the gemini handler class.
2. Implement the actual call_function in gemini handler, so handler handles the function calling.
3. Create a simple definition for agent and tools like adk root_agent and tools.
4. Add logic for combining user audio and model audio into a single mp3 file.