Fix handling of file: module URIs with non-ASCII characters

[HT154]

Resolves #653

[bioball]

Thanks for the fix!

We should also fix this in org.pkl.core.module.FileResolver#listElements(java.net.URI), and org.pkl.core.module.FileResolver#hasElement(java.net.URI).

That would handle cases like:

read("file:///path/to/日本語.pkl")

[HT154]

I refactored this into IoUtils, adopted it in FileResolved and also StackFrameTransformer, and added some more test coverage.

I suspect most other usage of Path.of in the codebase is at risk of similar issues. Really quite an inconvenient way for this API to work!

[bioball]

LGTM pending CI checks.

You need to run ./gradlew spotlessApply to fix some formatting woes.

[HT154]

Hmm I think this may be a legitimate difference in how things are handled on different OSs:

Changed content at line 6:
expecting:
  ["at 日本語_error#日本語 (file:///$snippetsDir/input/modules/%E6%97%A5%E6%9C%AC%E8%AA%9E_error.pkl)"]
but was:
  ["at 日本語_error#日本語 (file:///$snippetsDir/input/modules/日本語_error.pkl)"]

Is there a way to provide a different expectation or exclude this particular test on Windows? Or would it be best to just move this to CliEvaluatorTest where the URI diff can be substituted out of existence?

[bioball]

Let me look into that one for you; I have access to a Windows machine so it's much easier for me to figure this one out.