Automatic merge from submit-queue (batch tested with PRs 45481, 45463)

ThirdPartyResource example: added watcher example, code cleanup

**NOTE**: This is a cleaned and updated version of PR https://github.com/kubernetes/kubernetes/pull/43027

**What this PR does / why we need it**:
An example of using go-client for watching on ThirdPartyResource events (create/update/delete).