JSON5: Provide a way to read/write a comment using `JsonNode`

I'd like to parse JSON5 containing comments. `JsonReadFeature#ALLOW_JAVA_COMMENTS` ignores comments when deserializing a JSON into a `JsonNode`.
https://github.com/FasterXML/jackson-core/blob/0fbb52961c5092d7d1f8e8f620b719f9eff48fcd/src/main/java/com/fasterxml/jackson/core/json/ReaderBasedJsonParser.java#L2521-L2523
As a result, we lose the comment information and cannot read/recover the original content from the parsed `JsonNode`.
A commentable `JsonNode` is useful so as to retrieve the original comment and serialize the JsonNode to JSON5 format.