App router can't handle non-English routes

[ShahriarKh]

Goals

1. Allow non-English routes in folder names.

Non-Goals

1. Handle non-English routes in dynamic paths (like blog/[non-english-slug]/page.jsx). it's already supported.

Background

Currently, only english-routes/page.jsx are supported and routes including non-English characters like نوشته/page.jsx , ねこ/page.jsx or 🙂/page.jsx are not recognized.

It is possible to use the encoded value as the folder name (like %D9%86%D9%88%D8%B4%D8%AA%D9%87/page.jsx), but it's obviously unreadable.
Using rewrites is another workaround, but is extra work.

Proposal

If the router handle the decoding/encoding in the background, we can easily use different languages for folder names.