PR: Fix Autopath and Path for primitive types

[vonBrax]

🎁 Pull Request

• Used a clear / meaningful title for this pull request
• Tested the changes in your own code (on your projects)
• Added / Edited tests to reflect changes (tests folder)
• Have read the Contributing part of the Readme
• Passed npm test

Fixes

#246
#228

Why have you made changes?

To fix the above mentioned issues. Autopath currently does not work for primitive types since they don't have a "next path".

What changes have you made?

• Added a new type CurrentPath in Autopath to retrieve the value of the current path if there's no next path, using the inverse logic for NextPath
• Added a filter in Path to exclude methods from primitive types, since Path currently return their types (ex: a.someStr.toUpperCase returns () => string). This way Path and Autopath have a more consistent behavior when working together.

What tests have you updated?

• tested primitive types, array indexes and functions in tests/Function.ts
• tested paths to primitive methods in tests/Object.ts

Is there any breaking changes?

• Yes, I changed the public API & documented it
• Yes, I changed existing tests
• No, I added to the public API & documented it
• No, I added to the existing tests
• I don't know

[gautelo]

Any chance you can have a look at this @millsp ? AutoPath is a pretty cool feature, so would be nice if it could get fixed. 🙏