har-to-k6 Feat/error improvements

[EdvinasDaugirdas]

Clean up InvalidArchiveError error messages and extend with two properties:

• path: specifies the full path where the validation error has happened
• indexes: specifies the indexes where the validation error has happened

Example from CLI:

Before:

After:

---

Example from programmatic use:

Before:

After:

[w1kman]

isPlainObject is pretty strict. I stumbled upon the "... must be an Object" error and had a WTF-moment when I indeed passed an Object.

non-negative is more readable and arguably a more correct form of nonnegative.

[EdvinasDaugirdas]

@w1kman agree with your suggestions. Updated the PR accordingly.

[w1kman]

LGTM!