Escape quoted parameter names the way parse understands

[naveentehrpariya]

stringifyName uses JSON.stringify to quote non-identifier parameter names, but parse only recognizes a backslash as escaping the next literal character. The two schemes agree for \" and \\ — and diverge for every character JSON escapes into a sequence (\t, \n, \uXXXX, …), silently corrupting the round-trip:

const a = parse(':"a\tb"'); // name === 'a\tb' (tab is legal inside quotes)
const s = stringify(a);      // ':"a\tb"'  (JSON-escaped)
const b = parse(s);          // name === 'atb'  ← backslash stripped, 't' kept

This changes which parameter a compiled/matched route produces, with no error anywhere.

The fix quotes names by escaping only " and \ and emitting all other characters directly, which parse reads back unchanged.

Also adds stringify cases for a control character and quote/backslash in names, plus a round-trip assertion that parse(stringify(data)) reproduces the original tokens for every stringify case — that assertion fails on master for the new cases and passes here.

[krzysdz]

Isn't this a duplicate of #445?

[blakeembrey]

Thanks @krzysdz. I'm going to close this in favor of the first PR.