Remove the "ShieldType" concept (#430)

# What does this PR do?

This PR kills the notion of "ShieldType". The impetus for this is the
realization:

> Why is keyword llama-guard appearing so many times everywhere,
sometimes with hyphens, sometimes with underscores?

Now that we have a notion of "provider specific resource identifiers"
and "user specific aliases" for those and the fact that this works with
models ("Llama3.1-8B-Instruct" <> "fireworks/llama-3pv1-..."), we can
follow the same rules for Shields.

So each Safety provider can make up a notion of identifiers it has
registered. This already happens with Bedrock correctly. We just
generalize it for Llama Guard, Prompt Guard, etc.

For Llama Guard, we further simplify by just adopting the underlying
model name itself as the identifier! No confusion necessary.

While doing this, I noticed a bug in our DistributionRegistry where we
weren't scoping identifiers by type. Fixed.

## Feature/Issue validation/testing/test plan

Ran (inference, safety, memory, agents) tests with ollama and fireworks
providers.

llama_stack/apis/datasets/datasets.py

@@ -38,7 +38,6 @@ class Dataset(CommonDatasetFields, Resource):
         return self.provider_resource_id
 
 
-@json_schema_type
 class DatasetInput(CommonDatasetFields, BaseModel):
     dataset_id: str
     provider_id: Optional[str] = None

llama_stack/apis/eval_tasks/eval_tasks.py

@@ -34,7 +34,6 @@ class EvalTask(CommonEvalTaskFields, Resource):
         return self.provider_resource_id
 
 
-@json_schema_type
 class EvalTaskInput(CommonEvalTaskFields, BaseModel):
     eval_task_id: str
     provider_id: Optional[str] = None

llama_stack/apis/memory_banks/memory_banks.py

@@ -122,7 +122,6 @@ MemoryBank = Annotated[
 ]
 
 
-@json_schema_type
 class MemoryBankInput(BaseModel):
     memory_bank_id: str
     params: BankParams

llama_stack/apis/models/models.py

@@ -32,7 +32,6 @@ class Model(CommonModelFields, Resource):
         return self.provider_resource_id
 
 
-@json_schema_type
 class ModelInput(CommonModelFields):
     model_id: str
     provider_id: Optional[str] = None

llama_stack/apis/safety/client.py

@@ -27,7 +27,7 @@ async def get_client_impl(config: RemoteProviderConfig, _deps: Any) -> Safety:
 
 
 def encodable_dict(d: BaseModel):
-    return json.loads(d.json())
+    return json.loads(d.model_dump_json())
 
 
 class SafetyClient(Safety):
@@ -80,7 +80,7 @@ async def run_main(host: str, port: int, image_path: str = None):
         )
         cprint(f"User>{message.content}", "green")
         response = await client.run_shield(
-            shield_id="llama_guard",
+            shield_id="Llama-Guard-3-1B",
             messages=[message],
         )
         print(response)

llama_stack/apis/scoring_functions/scoring_functions.py

@@ -96,7 +96,6 @@ class ScoringFn(CommonScoringFnFields, Resource):
         return self.provider_resource_id
 
 
-@json_schema_type
 class ScoringFnInput(CommonScoringFnFields, BaseModel):
     scoring_fn_id: str
     provider_id: Optional[str] = None

llama_stack/apis/shields/client.py

@@ -37,7 +37,6 @@ class ShieldsClient(Shields):
     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]],
@@ -47,7 +46,6 @@ class ShieldsClient(Shields):
                 f"{self.base_url}/shields/register",
                 json={
                     "shield_id": shield_id,
-                    "shield_type": shield_type,
                     "provider_shield_id": provider_shield_id,
                     "provider_id": provider_id,
                     "params": params,
@@ -56,12 +54,12 @@ class ShieldsClient(Shields):
             )
             response.raise_for_status()
 
-    async def get_shield(self, shield_type: str) -> Optional[Shield]:
+    async def get_shield(self, shield_id: str) -> Optional[Shield]:
         async with httpx.AsyncClient() as client:
             response = await client.get(
                 f"{self.base_url}/shields/get",
                 params={
-                    "shield_type": shield_type,
+                    "shield_id": shield_id,
                 },
                 headers={"Content-Type": "application/json"},
             )

llama_stack/apis/shields/shields.py

@@ -4,7 +4,6 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 
-from enum import Enum
 from typing import Any, Dict, List, Literal, Optional, Protocol, runtime_checkable
 
 from llama_models.schema_utils import json_schema_type, webmethod
@@ -13,16 +12,7 @@ from pydantic import BaseModel
 from llama_stack.apis.resource import Resource, ResourceType
 
 
-@json_schema_type
-class ShieldType(Enum):
-    generic_content_shield = "generic_content_shield"
-    llama_guard = "llama_guard"
-    code_scanner = "code_scanner"
-    prompt_guard = "prompt_guard"
-
-
 class CommonShieldFields(BaseModel):
-    shield_type: ShieldType
     params: Optional[Dict[str, Any]] = None
 
 
@@ -59,7 +49,6 @@ class Shields(Protocol):
     async def register_shield(
         self,
         shield_id: str,
-        shield_type: ShieldType,
         provider_shield_id: Optional[str] = None,
         provider_id: Optional[str] = None,
         params: Optional[Dict[str, Any]] = None,