Fix rendering error on Judgement form with empty Submission
Fix deletion of Judgement that was never even saved.
Fix event-based filtering in submission listing
Merge branch 'hotfix/1.2.5'

Fixes:
- Rendering error of JudgementForm when Submission has no language set
- Deletion of Judgement that was never saved (e.g. empty Judgement on
  first save)
- Event-based filtering in submission listing