Cache DNS requests

[Mika56]

When doing checks in bulk, having a cache on top of the DNS requests would be nice

[Mika56]

It should be trivial to create a class implementing DNSRecordGetterInterface using a psr16 cache

use Psr\SimpleCache\CacheInterface;

class DNSRecordCachingGetter implements DNSRecordGetterInterface
{
    public function __construct(DNSRecordGetterInterface $recordGetter, CacheInterface $cache, int $ttl = 600)
}