HTTP support

[dlemper]

This represents the implementation for HTTP communication, which may be the base for Github and Nextcloud support on the client side.

There are two native methods for HTTP communication in the browser:

• XMLHttpRequest
• fetch

fetch is the newer one and preferred over XMLHttpRequest, if the browser supports it (all recent browsers do). There is also a polyfill available.

In addition there are quite a few libraries, like axios, which use either fetch or XMLHttpRequest to provide a better experience at development at the cost of more code.

In our case, I would suggest building a thin wrapper around fetch to accomplish everything needed.