Adds IPv6 support

* Based on https://github.com/jeremykendall/php-domain-parser/pull/35
* Only relevant if https://github.com/auraphp/Aura.Uri/pull/25 is merged
* If https://github.com/auraphp/Aura.Uri/pull/25 is merged, the only additional change is https://github.com/jeremykendall/Aura.Uri/commit/0857cc23f1f0d0b751c762b33d8cd72cbef1bfa6