fix: handle string output with streams

[dainiusjocas]

This PR is a partial fix/hack for the cases when the jq script produces multiple outputs, e.g.

$ jq '.[]' <<<'[1,2,3]'

The problem was that this lib returned only the last emitted JSON entity.

In order not to introduce severe breaking changes, the following behavior is introduced:

1. For cases when the output is a string, multiple outputs are joined by a new line.
2. When JsonNode is expected the output is always ArrayNode which extends both JsonNode and Iterable.

With these changes, the types returned are the same as previously but values changed significantly in some cases (so the breaking changes are masquerading as "fixes"). The overall behavior ends up being "tricky".

BREAKING CHANGES!

What's next:

• a new function that returns Iterable of JsonNodes Function to accept  JsonNode and return Collection #39
• Expose transducer interface Transducer based interface #40

[charles-dyfis-net]

Using newline separators could be messy if we supported a raw-output mode, since that use case would create ambiguity between newlines within content and newlines separating content; but so long as that's not intended, this seems perfectly reasonable. (And even if that is a direction this project wanted to go in, users to whom it mattered could request json-node output)

[dainiusjocas]

Using newline separators could be messy if we supported a raw-output mode, since that use case would create ambiguity between newlines within content and newlines separating content; but so long as that's not intended, this seems perfectly reasonable. (And even if that is a direction this project wanted to go in, users to whom it mattered could request json-node output)

I agree that using new lines is messy, but for now IMO, it is better than "just return the last emit" which is clearly wrong. As for the JsonNode return case, nothing really changes. Legacy.

In #39 I'll introduce an API that will be simpler and would return Iterable as it is done in gojq. And with #40 I believe most of the normal JQ functionality could be properly implemented with a sequence of configurable transducers.