Implement Node's safe decode alternative

[niftylettuce]

We should try to match Node behavior in the browser, and to do so, instead of returning null, we'd need to implement Node's fallback:

https://github.com/nodejs/node/blob/908292cf1f551c614a733d858528ffb13fb3a524/lib/querystring.js#L397-L403 which specifically uses https://github.com/nodejs/node/blob/908292cf1f551c614a733d858528ffb13fb3a524/lib/querystring.js#L67-L108

[lpinca]

FWIW I think compatibility with Node.js querystring module has never been an objective. This module does not even handle arrays.