Add tugboat QA issue preview support

Memory limit reached, never had this before on Drupal.org tugboat

Works with 10.3 image. Seems 11 is not working yet. But all good.

We did not work before with tugboat. If you say it is all fine I will merge.

All fine (see status "ready" above). Very helpful in UI-facing issues and for manual testing in issues.

Merged. Thank you very much!