[MNY-196] SDK: Add SwapWidget render event (#8113)

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## PR-Codex overview
This PR introduces a new query using `useQuery` from `@tanstack/react-query` in the `SwapWidget` component to track the rendering event of the swap widget.

### Detailed summary
- Added `useQuery` to the `SwapWidget` component.
- Implemented a query function that calls `trackPayEvent` to log the rendering of the swap widget.
- The tracking event includes the `client` from `props` and an event identifier `"ub:ui:swap_widget:render"`.

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<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

* **Chores**
  * Added background telemetry for the Swap Widget to record render events for analytics. It runs automatically when the widget is displayed, requires no configuration, and does not change the UI or user experience. This helps track usage and adoption to inform future improvements.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: MananTank

packages/thirdweb/src/react/web/ui/Bridge/swap-widget/SwapWidget.tsx

@@ -1,6 +1,8 @@
 "use client";
 
+import { useQuery } from "@tanstack/react-query";
 import { useCallback, useEffect, useState } from "react";
+import { trackPayEvent } from "../../../../../analytics/track/pay.js";
 import type { Buy, Sell } from "../../../../../bridge/index.js";
 import type { TokenWithPrices } from "../../../../../bridge/types/Token.js";
 import type { ThirdwebClient } from "../../../../../client/client.js";
@@ -241,6 +243,17 @@ export type SwapWidgetProps = {
  * @bridge
  */
 export function SwapWidget(props: SwapWidgetProps) {
+  useQuery({
+    queryFn: () => {
+      trackPayEvent({
+        client: props.client,
+        event: "ub:ui:swap_widget:render",
+      });
+      return true;
+    },
+    queryKey: ["swap_widget:render"],
+  });
+
   return (
     <SwapWidgetContainer
       theme={props.theme}