feat: Code scanner Provider impl for moderations api (#3100)

# What does this PR do?
Add CodeScanner implementations

## Test Plan
`SAFETY_MODEL=CodeScanner LLAMA_STACK_CONFIG=starter uv run pytest -v
tests/integration/safety/test_safety.py
--text-model=llama3.2:3b-instruct-fp16
--embedding-model=all-MiniLM-L6-v2 --safety-shield=ollama`

This PR need to land after this
https://github.com/meta-llama/llama-stack/pull/3098

llama_stack/core/routers/safety.py

@@ -6,9 +6,7 @@
 
 from typing import Any
 
-from llama_stack.apis.inference import (
-    Message,
-)
+from llama_stack.apis.inference import Message
 from llama_stack.apis.safety import RunShieldResponse, Safety
 from llama_stack.apis.safety.safety import ModerationObject
 from llama_stack.apis.shields import Shield
@@ -68,6 +66,7 @@ class SafetyRouter(Safety):
             list_shields_response = await self.routing_table.list_shields()
 
             matches = [s.identifier for s in list_shields_response.data if model == s.provider_resource_id]
+
             if not matches:
                 raise ValueError(f"No shield associated with provider_resource id {model}")
             if len(matches) > 1: