use logging instead of prints (#499)

# What does this PR do?

This PR moves all print statements to use logging. Things changed:
- Had to add `await start_trace("sse_generator")` to server.py to
actually get tracing working. else was not seeing any logs
- If no telemetry provider is provided in the run.yaml, we will write to
stdout
- by default, the logs are going to be in JSON, but we expose an option
to configure to output in a human readable way.

llama_stack/providers/inline/agents/meta_reference/tools/builtin.py

@@ -5,6 +5,7 @@
 # the root directory of this source tree.
 
 import json
+import logging
 import re
 import tempfile
 
@@ -12,7 +13,6 @@ from abc import abstractmethod
 from typing import List, Optional
 
 import requests
-from termcolor import cprint
 
 from .ipython_tool.code_execution import (
     CodeExecutionContext,
@@ -27,6 +27,9 @@ from llama_stack.apis.agents import *  # noqa: F403
 from .base import BaseTool
 
 
+log = logging.getLogger(__name__)
+
+
 def interpret_content_as_attachment(content: str) -> Optional[Attachment]:
     match = re.search(TOOLS_ATTACHMENT_KEY_REGEX, content)
     if match:
@@ -383,7 +386,7 @@ class CodeInterpreterTool(BaseTool):
             if res_out != "":
                 pieces.extend([f"[{out_type}]", res_out, f"[/{out_type}]"])
                 if out_type == "stderr":
-                    cprint(f"ipython tool error: ↓\n{res_out}", color="red")
+                    log.error(f"ipython tool error: ↓\n{res_out}")
 
         message = ToolResponseMessage(
             call_id=tool_call.call_id,