reverse-string: string with newline

This came up in the bash track: what to do with strings containing newlines?

A common solution in shell would be to pipe the input into `rev` which would treat the input as _lines_ and not _a single string_.

Suggest a new case:
```json
{
"description": "with a newline",
"property": "reverse",
"input": {
"value": "Hello,\nWorld!"
},
"expected": "!dlroW\n,olleH"
}
```