[Feature] Implement high-level function `fetch()` building on top of the standard fetch API

[Luna-Klatzer]

Is there an existing proposal for this?

• I have searched the existing issues

This feature does not exist in the latest version

• I am using the latest version

Proposal

Implement a standard async-based fetch API allowing standard HTTP requests to be made given a specific target URL. This should resemble the standard fetch JavaScript API, which is the default web request interface in browser and Node v18+ environments.

Exact behaviour / changes you want

• Implement global function fetch(), which performs a given request and returns the request as a promise.

[Luna-Klatzer]

Whether or not Kipper decides to implement a blocking fetch() or straight away go to async (#727) is to be decided.