Automatic merge from submit-queue (batch tested with PRs 51401, 54056, 54977, 55017, 55052). 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>.
extensions: remove TPR remnants
The extensions group still had the TPR types + generated client. Having this in the codebase doesn't create any problems but would be good to clean up, especially since TPR access has been removed in 1.8.
**Release note**:
```release-note
NONE
```
/assign @sttts @deads2k