Automatic merge from submit-queue
Add a package for handling version numbers (including non-"Semantic" versions)
As noted in #32401, we are using Semantic Version-parsing libraries to parse version numbers that aren't necessarily "Semantic". Although, contrary to what I'd said there, it turns out that this wasn't actually currently a problem for the iptables code, because the regexp used to extract the version number out of the "iptables --version" output only pulled out three components, so given "iptables v1.4.19.1", it would have extracted just "1.4.19". Still, it could be a problem if they later release "1.5" rather than "1.5.0", or if we eventually need to _compare_ against a 4-digit version number.
Also, as noted in #23854, we were also using two different semver libraries in different parts of the code (plus a wrapper around one of them in pkg/version).
This PR adds pkg/util/version, with code to parse and compare both semver and non-semver version strings, and then updates kubernetes to use it everywhere (including getting rid of a bunch of code duplication in kubelet by making utilversion.Version implement the kubecontainer.Version interface directly).
Ironically, this does not actually allow us to get rid of either of the vendored semver libraries, because we still have other dependencies that depend on each of them. (cadvisor uses blang/semver and etcd uses coreos/go-semver)
fixes#32401, #23854