Support Cloudflare-style resolution

https://developers.cloudflare.com/pages/configuration/serving-pages/#route-matching

> If an HTML file is found with a matching path to the current route requested, Pages will serve it. Pages will also redirect HTML pages to their extension-less counterparts: for instance, `/contact.html` will be redirected to `/contact`, and `/about/index.html` will be redirected to `/about/`.

Read the linked Cloudflare Pages route-matching documentation first. Then locate the existing path-resolution entry point in the Gradle plugins and add coverage for extensionless HTML routes, redirects from .html paths, and index.html directory routes. Done means the supported routes resolve and redirect as described.

Scritto dal modello di indicizzazione a partire dal testo della issue.