feat!: use ky with limited retries instead of axios (#203)

[hunterckx]

I've updated the api function to create a new Axios instance each time, rather than using a singleton, so that each instance can have its own retry process

• ES modules in tests have to be imported after any relevant module mocks are done, so some of the imports in tests are changed to be async
• Since entityURL doesn't appear to have been doing anything, I've removed it entirely

[frano-m]

Nice @hunterckx 🎸 .