use WWW::Form::UrlEncoded's build_urlencoded

use WWW::Form::UrlEncoded's build_urlencoded

If able to support arrayref value like this

    say build_url(
        base_uri => 'http://api.example.com/',
        path => '/v1/entries',
        query => [
            id => [3,4,5]
        ]
    );

And if WWW::Form::UrlEncoded::XS is available, build_urlencoded will be more fast.