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/distributions/ci-tests/run.yaml

@@ -135,6 +135,8 @@ providers:
     provider_type: inline::llama-guard
     config:
       excluded_categories: []
+  - provider_id: code-scanner
+    provider_type: inline::code-scanner
   agents:
   - provider_id: meta-reference
     provider_type: inline::meta-reference
@@ -223,6 +225,9 @@ shields:
 - shield_id: llama-guard
   provider_id: ${env.SAFETY_MODEL:+llama-guard}
   provider_shield_id: ${env.SAFETY_MODEL:=}
+- shield_id: code-scanner
+  provider_id: ${env.CODE_SCANNER_MODEL:+code-scanner}
+  provider_shield_id: ${env.CODE_SCANNER_MODEL:=}
 vector_dbs: []
 datasets: []
 scoring_fns: []