list responses

# What does this PR do?


## Test Plan

docs/_static/llama-stack-spec.yaml

@@ -349,6 +349,53 @@ paths:
               $ref: '#/components/schemas/CreateAgentTurnRequest'
         required: true
   /v1/openai/v1/responses:
+    get:
+      responses:
+        '200':
+          description: A ListOpenAIResponseObject.
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ListOpenAIResponseObject'
+        '400':
+          $ref: '#/components/responses/BadRequest400'
+        '429':
+          $ref: >-
+            #/components/responses/TooManyRequests429
+        '500':
+          $ref: >-
+            #/components/responses/InternalServerError500
+        default:
+          $ref: '#/components/responses/DefaultError'
+      tags:
+        - Agents
+      description: List all OpenAI responses.
+      parameters:
+        - name: after
+          in: query
+          description: The ID of the last response to return.
+          required: false
+          schema:
+            type: string
+        - name: limit
+          in: query
+          description: The number of responses to return.
+          required: false
+          schema:
+            type: integer
+        - name: model
+          in: query
+          description: The model to filter responses by.
+          required: false
+          schema:
+            type: string
+        - name: order
+          in: query
+          description: >-
+            The order to sort responses by when sorted by created_at ('asc' or 'desc').
+          required: false
+          schema:
+            $ref: '#/components/schemas/Order'
     post:
       responses:
         '200':
@@ -7106,6 +7153,80 @@ components:
       required:
         - data
       title: ListModelsResponse
+    ListOpenAIResponseObject:
+      type: object
+      properties:
+        data:
+          type: array
+          items:
+            $ref: '#/components/schemas/OpenAIResponseObjectWithInput'
+        has_more:
+          type: boolean
+        first_id:
+          type: string
+        last_id:
+          type: string
+        object:
+          type: string
+          const: list
+          default: list
+      additionalProperties: false
+      required:
+        - data
+        - has_more
+        - first_id
+        - last_id
+        - object
+      title: ListOpenAIResponseObject
+    OpenAIResponseObjectWithInput:
+      type: object
+      properties:
+        created_at:
+          type: integer
+        error:
+          $ref: '#/components/schemas/OpenAIResponseError'
+        id:
+          type: string
+        model:
+          type: string
+        object:
+          type: string
+          const: response
+          default: response
+        output:
+          type: array
+          items:
+            $ref: '#/components/schemas/OpenAIResponseOutput'
+        parallel_tool_calls:
+          type: boolean
+          default: false
+        previous_response_id:
+          type: string
+        status:
+          type: string
+        temperature:
+          type: number
+        top_p:
+          type: number
+        truncation:
+          type: string
+        user:
+          type: string
+        input:
+          type: array
+          items:
+            $ref: '#/components/schemas/OpenAIResponseInput'
+      additionalProperties: false
+      required:
+        - created_at
+        - id
+        - model
+        - object
+        - output
+        - parallel_tool_calls
+        - status
+        - input
+      title: OpenAIResponseObjectWithInput
     ListProvidersResponse:
       type: object
       properties: