curl to axios

Turns a `curl` command into an axios request config: method, url, headers, `data` for the body and `auth` for basic credentials.

axios differs from fetch in ways that change the translation. The body is `data` rather than `body` and is serialised for you, so a JSON object goes in as an object rather than as a string — passing `JSON.stringify(…)` to axios and also setting a JSON content type is a common way to end up with a double-encoded body. Basic auth is a first-class field. `-u user:pass` becomes `auth: { username, password }` and axios builds the header, which is tidier than the `btoa` dance fetch needs, and works in Node where `btoa` historically did not exist. The other real difference is errors. axios rejects on a 4xx or 5xx, fetch resolves and leaves you to check `response.ok`. Code translated from one to the other without adjusting the error handling will either swallow failures or throw where it used to continue — worth checking after any conversion in either direction.