Validate Punycoded TLDs

[BreyndotEchse]

Method isValid must return true for IDN top level domains.

[Maks3w]

Please refactor using data providers.

Also split the test in two tests, one when is valid and another one when is not

[Maks3w]

When refactor please add a description for each case using the key of the array

['invalid foo' => 'xn--3-owe4au9mpa.xn--xkc2al3hye2a']

[BreyndotEchse]

Only for testAdditionalPunycodedTLDs or also for testAdditionalUTF8TLDs (merged)?

Example dataProvider (valid hostnames):

public function validTLDHostnames()
{
    // @codingStandardsIgnoreStart
    return [
        'test123.онлайн' => 'test123.онлайн',
        'test123.онлайн' => 'test123.xn--80asehdb',
        'тест.рф'        => 'тест.рф',
        'тест.рф'        => 'xn--e1aybc.xn--p1ai',
        'туршилтын.мон'  => 'туршилтын.мон',
        'туршилтын.мон'  => 'xn--h1aggjjdd5b4a.xn--l1acc',
    ];
    // @codingStandardsIgnoreEnd
}

[Maks3w]

I'll appreciate if you can do it testAdditionalUTF8TLDs as well.

What I miss with the descriptions I don't quickly understand why that case is significative.

return [
        'UTF8 TLD' => 'test123.онлайн',
        'Punyencoded TLD' => 'test123.xn--80asehdb',
...
    ];