Inject route-change script for Live Preview path sync @W-21574818@

[deepu-mungamuri94]

What does this PR do?

Keeps the Live Preview path input in sync when users navigate inside the webapp (e.g., clicking "Go to Home" or other in-app links).

What this change does

• Injects a route-change script into HTML responses served by the proxy (wrapResponseForRouteInjection() in ProxyServer.ts).
• The script listens for route changes via:
  • history.pushState / replaceState
  • popstate
  • Navigation API
• When the route changes, it sends a routeChanged message to the parent (Live Preview webview), which updates the path input accordingly.

Without this change

• The path input in the Live Preview toolbar stays stale after in-app navigation.
• Users clicking links like "Go to Home" would see the path remain at / instead of updating to /home.

What issues does this PR fix or reference?

@W-21574818@