Resource oriented design for shields (#399)

* init

* working bedrock tests

* bedrock test for inference fixes

* use env vars for bedrock guardrail vars

* add register in meta reference

* use correct shield impl in meta ref

* dont add together fixture

* right naming

* minor updates

* improved registration flow

* address feedback

---------

Co-authored-by: Dinesh Yeduguru <dineshyv@fb.com>

llama_stack/apis/shields/client.py

@@ -5,7 +5,6 @@
 # the root directory of this source tree.
 
 import asyncio
-import json
 
 from typing import List, Optional
 
@@ -26,27 +25,38 @@ class ShieldsClient(Shields):
     async def shutdown(self) -> None:
         pass
 
-    async def list_shields(self) -> List[ShieldDefWithProvider]:
+    async def list_shields(self) -> List[Shield]:
         async with httpx.AsyncClient() as client:
             response = await client.get(
                 f"{self.base_url}/shields/list",
                 headers={"Content-Type": "application/json"},
             )
             response.raise_for_status()
-            return [ShieldDefWithProvider(**x) for x in response.json()]
+            return [Shield(**x) for x in response.json()]
 
-    async def register_shield(self, shield: ShieldDefWithProvider) -> None:
+    async def register_shield(
+        self,
+        shield_id: str,
+        shield_type: ShieldType,
+        provider_shield_id: Optional[str],
+        provider_id: Optional[str],
+        params: Optional[Dict[str, Any]],
+    ) -> None:
         async with httpx.AsyncClient() as client:
             response = await client.post(
                 f"{self.base_url}/shields/register",
                 json={
-                    "shield": json.loads(shield.json()),
+                    "shield_id": shield_id,
+                    "shield_type": shield_type,
+                    "provider_shield_id": provider_shield_id,
+                    "provider_id": provider_id,
+                    "params": params,
                 },
                 headers={"Content-Type": "application/json"},
             )
             response.raise_for_status()
 
-    async def get_shield(self, shield_type: str) -> Optional[ShieldDefWithProvider]:
+    async def get_shield(self, shield_type: str) -> Optional[Shield]:
         async with httpx.AsyncClient() as client:
             response = await client.get(
                 f"{self.base_url}/shields/get",
@@ -61,7 +71,7 @@ class ShieldsClient(Shields):
             if j is None:
                 return None
 
-            return ShieldDefWithProvider(**j)
+            return Shield(**j)
 
 
 async def run_main(host: str, port: int, stream: bool):