Automatic merge from submit-queue (batch tested with PRs 59276, 51042, 58973, 59377, 59472). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Allow passing request-timeout from NewRequest all the way down
**What this PR does / why we need it**:
Currently if you pass `--request-timeout` it's not passed all the way down to the actual request object. There's a separate field on the `Request` object that allows setting that timeout, but it's not taken from that flag.
@smarterclayton @deads2k ptal, this is coming from https://github.com/openshift/origin/pull/13701
Previously, the fake RESTClient in client-go required a Registry. It
used the Registry to fetch the GroupVersion for the fake client.
However, the way it did so was dubious in some cases (it hard-coded the
default API group in places), and not strictly necssary.
This updates the fake client to just recieve the GroupVersion and
internal group name directly, instead of requiring a Registry, so that
it can be consumed in unit tests where a Registry isn't necessarily
readily available (e.g. elsewhere in client-go).
