Automatic merge from submit-queue. 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>.

E2e path utils

**What this PR does / why we need it**:

A bunch of useful methods for getting k8s paths and stuff are secreted away in `e2e_node`. This PR pulls them out so they can be used in other E2E method.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:



**Special notes for your reviewer**:
This is motivated by the upcoming kubeadm-specific E2E tests. Those tests will be added in a follow-up to this PR.

**Release note**:

```release-note
NONE
```