Replace wpapi dependency

[soup-bowl]

Looks like the official WordPress NodeJS library WPAPI has been silently sunset a while back.

Since the last update was 4 years ago, this library is clearly deprecated and will gradually - if not already - start becoming vulnurable. This should ideally be replaced.

Current options are:

• Switch to using direct fetches to the relevant website APIs.
  • Axios was used before.
  • Building a small library might be more beneficial on this route.
• Maintain a fork of WPAPI.
  • Check code quality beforehand - several years lacking updates might make maintenance difficult.