Automatic merge from submit-queue (batch tested with PRs 40046, 40073, 40547, 40534, 40249)
Issue #13501 - printEvent Source to much more cleaner
Create a formatEventSource func and use it.
**What this PR does / why we need it**:
Adds a smarter way to print EventSource, removing "{ }" and the eventual extra ", " when Host is empty.
It was also reported in OpenShift issue https://github.com/openshift/origin/issues/6586
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#13501
**Special notes for your reviewer**:
I have used this new func in all user facing printouts, but there are other places where EventSource are printed to logs, like DumpEventsInNamespace in test/e2e/framework/util.go for instance.
Don't know if I should correct there too...
**Release note**:
```release-note
Improve formatting of EventSource in kubectl get and kubectl describe
```