Automatic merge from submit-queue (batch tested with PRs 62460, 64480, 63774, 64540, 64337). 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>.
use subtest for table units (pkg/master)
**What this PR does / why we need it**:
Go 1.7 added the subtest feature which can make table-driven tests much easier to run and debug. Many table-driven tests in pkg/kubectl are not using this feature.
/kind cleanup
Further reading: [Using Subtests and Sub-benchmarks](https://blog.golang.org/subtests)
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
This adds context to all the relevant cloud provider interface signatures.
Callers of those APIs are currently satisfied using context.TODO().
There will be follow on PRs to push the context through the stack.
For an idea of the full scope of this change please look at PR #58532.