Remove API interface

[peterjan]

PULL REQUEST

Overview

This PR removes the skyd package with the API interface in favor of using the client.
This makes it so we stop repeating all HTTP request logic everywhere and just make
use of the client as much as possible.

We still keep the API tester because I just think it's useful keep the simple unit tests
for our handlers.

Example for Visual Changes

N/A

Checklist

Review and complete the checklist to ensure that the PR is complete before assigned to an approver.

• All new methods or updated methods have clear docstrings
• Testing added or updated for new methods
• Verify if any changes impact the WebPortal Health Checks
• Approriate documentation updated
• Changelog file created

Issues Closed

Closes #26

[ro-tex]

LGTM in general. I would fix that name but it can be a F/U.