Sensible timeout, retry etc. defaults in Requests GET / POST / PUT / DELETE methods

As per https://docs.python-requests.org/en/latest/user/quickstart/#timeouts

(also I've seen some mutterings that httpx has been a nice thing to move to - https://www.python-httpx.org/compatibility/ - but I have more experience with Requests so my instinct is to stick with that for now...)