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/components/responses/items/generic-item.tsx

@@ -0,0 +1,37 @@
+import {
+  MessageBlock,
+  ToolCallBlock,
+} from "@/components/ui/message-components";
+import { BaseItem } from "../utils/item-types";
+
+interface GenericItemProps {
+  item: BaseItem;
+  index: number;
+  keyPrefix: string;
+}
+
+export function GenericItemComponent({
+  item,
+  index,
+  keyPrefix,
+}: GenericItemProps) {
+  // Handle other types like function calls, tool outputs, etc.
+  const itemData = item as Record<string, unknown>;
+
+  const content = itemData.content
+    ? typeof itemData.content === "string"
+      ? itemData.content
+      : JSON.stringify(itemData.content, null, 2)
+    : JSON.stringify(itemData, null, 2);
+
+  const label = keyPrefix === "input" ? "Input" : "Output";
+
+  return (
+    <MessageBlock
+      key={`${keyPrefix}-${index}`}
+      label={label}
+      labelDetail={`(${itemData.type})`}
+      content={<ToolCallBlock>{content}</ToolCallBlock>}
+    />
+  );
+}