Filter url_encode was extended for objects

[ahtohbi4]

The ability to encode an object to URL by the filter url_encode was added according to the Twig PHP.

const data = {
    foo: {
        baz: 'bar',
    },
};
const template = twig({ data: '{{ foo|url_encode }}' });

console.log(template.render(data)); // => "foo%5Bbaz%5D=bar"

[ahtohbi4]

What about this PR? Are there some doubts?

[RobLoach]

Thanks a lot. Looks pretty good, is there anything missing before we merge it?

[ahtohbi4]

At first, were written tests according to Twig PHP documentation, after that was written the code... I hope I missed nothing. 🙄