This changes the text registration so that tags for which the framework has a
dedicated API (features, feature gates, slow, serial, etc.) those APIs are
used.
Arbitrary, custom tags are still left in place for now.
Using WaitTimeoutForPodRunningInNamespace followed by ExpectError was not very
precise (any error passed the check, not just the expected timeout) and
hard to read. Now the test's expectation is spelled out explicitly: the pod
must stay in pending.
All code must use the context from Ginkgo when doing API calls or polling for a
change, otherwise the code would not return immediately when the test gets
aborted.