Routes builder improvement

[yoannfleurydev]

As a follow up, we can probably use https://developer.mozilla.org/en-US/docs/Web/API/URL/URL and https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/URLSearchParams to improve types and avoid to build string ourselves.

Originally posted by @yoannfleurydev in #498 (comment)