feat(ui): add views for Responses (#2293)

# What does this PR do?
* Add responses list and detail views
* Refactored components to be shared as much as possible between chat
completions and responses

## Test Plan
<img width="2014" alt="image"
src="https://github.com/user-attachments/assets/6dee12ea-8876-4351-a6eb-2338058466ef"
/>
<img width="2021" alt="image"
src="https://github.com/user-attachments/assets/6c7c71b8-25b7-4199-9c57-6960be5580c8"
/>

added tests

llama_stack/ui/lib/client.ts

@@ -0,0 +1,12 @@
+import LlamaStackClient from "llama-stack-client";
+import OpenAI from "openai";
+
+export const client =
+  process.env.NEXT_PUBLIC_USE_OPENAI_CLIENT === "true" // useful for testing
+    ? new OpenAI({
+        apiKey: process.env.NEXT_PUBLIC_OPENAI_API_KEY,
+        dangerouslyAllowBrowser: true,
+      })
+    : new LlamaStackClient({
+        baseURL: process.env.NEXT_PUBLIC_LLAMA_STACK_BASE_URL,
+      });