fix(csv-stringify): quote fields containing a carriage return

[sarathfrancis90]

A field holding a lone carriage return is written unquoted, because the quoting check only looks for the configured record_delimiter (\n by default). The parser treats both \r and \n as record delimiters, so the value gets split apart and the document no longer round-trips:

const { stringify } = require("csv-stringify/sync");
const { parse } = require("csv-parse/sync");

parse(stringify([["a\rb"]]));
// => [["a"], ["b"]]   (expected [["a\rb"]])

\n and \r\n are already quoted; only a bare \r slips through.

The fix: when the record delimiter is newline-based, quote any field that contains \r or \n. A custom, non-newline delimiter still leaves line breaks as data, so that behaviour is unchanged.

Found while fuzzing the stringify → parse round trip. Added a regression test; the escape-formulas test is updated since a \r-leading field is now correctly quoted. Full csv-stringify suite (202) and tsc pass.