fix(app): update event before calling request hook

[zsilbi]

🔗 Linked issue

Fixes #3150

❓ Type of change

• 🐞 Bug fix (a non-breaking change that fixes an issue)

📚 Description

event.context.nitro is currently initialized in the generic event handler of h3App.
The request hook is called in h3App.onRequest() which runs before the generic event handler.
By moving the nitro context initialization there, we can also provide the context for the listeners of the request hook.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[pi0]

Thanks, onRequest was added later we could move other init logic early here as well!