Update to match other HTTP wrapper projects

[owenvoke]

Description

It would be good to move this to HTTPlug to match my other projects:

• https://github.com/owenvoke/gitea-php
• https://github.com/owenvoke/ecologi-php
• https://github.com/owenvoke/poap-php
• https://github.com/owenvoke/unit3d-php

Possible implementation

Basically implement the same thing, and remove the DTOs from here.