### Description

This PR aims to improve/fix the PageView API doc sample for Web and Desktop platforms. On these platforms, mouse dragging gestures do not provide natural behavior similar to other desktop applications. This PR will add navigation buttons (indicators) so users can interact with the demo.

### Related issue

Fixes https://github.com/flutter/flutter/issues/135188

### Demo video

https://github.com/flutter/flutter/assets/104349824/0f9c60bd-8b18-404e-b5b6-1d594604de31