Simple HTTP requests library

[marzipankaiser]

This is a simple Proof-of-concept HTTP requests library in Effekt.
It forwards to the respective web/node APIs.
Additionally, it contains a (very much not production-ready) implementation of HTTP/1.1 in Effekt that reads/writes from/to Effekt streams (for integration with potential TCP bindings).

[jiribenes]

Some nice common methods, like get(url: String): Option[String] or sth.

We could follow the other io/... modules with a custom effect like:

interface HttpClient {
  def get(url: String, body: Option[String], headers: List[(String, String)]): Response
  def post(url: String, body: Option[String], headers: List[(String, String)]): Response
}

(+ async-/streaming-related stuff of course)

and then provide get(url) := do get(url, None, []) wrappers?

[marzipankaiser]

Apparently we could drop the node implementation and use fetch there, too; at least once we are sure all node versions we use are >=21: https://blog.logrocket.com/fetch-api-node-js/

[marzipankaiser]

For the dispatch, I'd wait for the resolution of #448.

[marzipankaiser]

Those (and the async iterator stuff) might be independently useful for other Node APIs (namely child_process) - do we have a convention where to put those kinds of "only for one backend, but used from common" things?

[marzipankaiser]

CI fails due to #1075.