idea: Define `http.Client` once in CLI

[TheJolman]

This doesn't matter too much since the CLI runs once and returns, but we are making multiple requests per instance due to the health check that we do prior to sending the "real" request.

Defining http.Client{} once and passing it around would be more efficient (not that it matters too much) but it's more of a code quality thing.

Low prio, mostly writing this so I don't forget about if this become more relevant in the future.