Add Netlify attribution to TRSS client page

The Adoptium hosted TRSS should provide attribution to Netlify for hosting it.

This can be through adding a footer to the index page. e.g.
```
diff --git a/test-result-summary-client/src/App.jsx b/test-result-summary-client/src/App.jsx
index 0519def..ac56b67 100644
--- a/test-result-summary-client/src/App.jsx
+++ b/test-result-summary-client/src/App.jsx
@@ -252,6 +252,11 @@ export default class App extends Component {



+
+
+
+
+


);
```

(I don't have a TRSS developer installation to test this change)

Start in test-result-summary-client/src/App.jsx and inspect the existing layout around the application content. Add the Netlify attribution footer described in the issue, then verify that the TRSS client page renders the footer with the Netlify link and image.

Written by the indexing model from the issue text.