[api] Support x-json-stream, add JsonGenerator writeNewLine()

Reference: https://en.wikipedia.org/wiki/JSON_streaming#Line-delimited_JSON

When looking at JsonGenerator API I do not see a mechanism to support `x-json-stream` type output using the "Line delimited JSON" format. Is there a way to produce it that I am missing? Otherwise, I would like to discuss and see if that would be something we could look to add?

### Background:
I have traditionally been using jackson core JsonGenerator which includes a [writeRaw(char)](https://github.com/FasterXML/jackson-core/blob/2.14/src/main/java/com/fasterxml/jackson/core/JsonGenerator.java#L1435) method that I can use to write the new line character.

In general for `x-json-stream` "line delimited JSON" we need to:
1. Ensuring "pretty" printing JSON is disabled / turned off
2. Write `\n` characters after each top level json object

Ideally I would like to see support for producing this via the JsonGenerator API. I believe that would mean adding a method to JsonGenerator like `writeNewLine()`.

The issue names the JsonGenerator API and references Jackson's JsonGenerator writeRaw(char); start by reviewing the repository's JsonGenerator definition and existing formatting or output tests. Confirm how a writeNewLine() API should interact with pretty printing and top-level values, then define completion as supported line-delimited JSON output with tests covering the behavior.

Written by the indexing model from the issue text.