[chore] Remove Trilead specific implementations

[Dohbedoh]

Actually move them to trilead-api, see jenkinsci/trilead-api-plugin#147.

Testing done

### Submitter checklist
- [ ] Make sure you are opening from a **topic/feature/bugfix branch** (right side) and not your main branch!
- [ ] Ensure that the pull request title represents the desired changelog entry
- [ ] Please describe what you did
- [ ] Link to relevant issues in GitHub or Jira
- [ ] Link to relevant pull requests, esp. upstream and downstream changes
- [ ] Ensure you have provided tests - that demonstrates feature works or fixes the issue

[olamy]

Thanks!

[jglick]

(pending discussion of logistics)