feat: add state/tool context management to live api

[Ruthvik-1411]

Resolves #48
Changelog:

1. Add basic state management for the live api boilerplate.
2. Added ToolContext a dict management class which handles setting, getting and clearing of the dict access to the high level functions in tool_context.py.
3. Functions can now read and update the shared tool context which is created per websocket session.
   • If they accept a ToolContext we ignore this argument when creating the function declaration using @function_tool.
   • If a function needs to use the tool context, it should define the tool context as a Mandatory Argument, not Optional.
4. Updated app.py to send the tool context each time when a function call is invoked.
   • Inside the call_function we check if the function being called uses the ToolContext by calling accepts_tool_context and then update the args accordingly to send the current context along with the existing args provided by the llm.