feat(tracer): add new field instrumentation

[zakahan]

Add fields to the tracer attrabute

• app.name: Add the app.name field in the agent_run, call_llm, and execute_tool stages respectively.
• agent.name: Add the agent.name field in the agent_run, call_llm, and execute_tool stages respectively.
• tool.name: Add the tool.name field in the execute_tool stage.

Special Instructions

• Since app.name is a field at the runner level, in runner.py, the injection of app_name is achieved by adding the following code:

        if getattr(self.agent, "tracers", None):
            for tracers in self.agent.tracers:
                tracers.set_app_name(self.app_name)

• Add after_tool_callback to implement field tracing of agent.name and app.name during the tool call stage