Router fails to resolve URL-encoded links

[c0ldra1n]

Describe the bug
Sapper router fails to route links with URL-encoded characters. That is, links that contain non-ascii characters like 가나다라(hangul).

Logs
GET http://localhost:3000/posts/%ED%85%8C%EC%8A%A4%ED%8A%B8 404 (Not Found)
which translates to http://localhost:3000/posts/테스트 and src/routes/posts/테스트.svelte exists.

To Reproduce
Use any links/routes that would produce a link with encoded characters. The generated code will include the encoded characters.

Expected behavior
The link should resolve according to the url-encoded string.

Stacktraces
No stacktraces were logged

Information about your Sapper Installation:

• Chrome 78.0.3904.108 (Official Build) (64-bit)

• macOS 10.14.6 (18G1012)

• Hosted locally

• Sapper version 0.27.9

• Svelte version 3.15.0

• Ran as dynamic application on dev environment

• Rollup

Severity
Such URL resolving technique is crucial for international audiences / developers of Sapper based websites.

Additional context
This issue can be simply resolved by adding a url-encoding function to all route related regex tests. I will add a pull request later on.