[meta] Improve translation robustness

[eu9ene]

This is a meta issue for tracking issues to improve the robustness of the translation models:

Tasks

Beta Give feedback

1. Create a dataset of short sentences for training and/or validation firefox-translations-training#514
   quality +1
2. Improve translation of short sentences firefox-translations-training#215
   quality +1
3. Ensure presence or absence of periods doesn't trigger wrong translations firefox-translations-training#177
   quality +1
4. Improve translation of URLs firefox-translations-training#736
   quality +1
5. Check if issues with short sentences were caused by bicleaner hard rules firefox-translations-training#903
   quality +1
6. Improve translation of social posts firefox-translations-training#737
   quality +1
7. Integrate OpusTrainer firefox-translations-training#161
   quality +1
   
8. Poor performance when translating ALL CAPS sentences firefox-translations-training#73
   quality +1
9. Issues with casing firefox-translations-training#129
   quality +1
10. Investigate issue with OpusTrainer typos firefox-translations-training#262
    quality +1
    
11. Support augmentation with inline noise firefox-translations-training#261
    quality +1
    
12. Ensure random whitespaces between characters don't trigger wrong translations firefox-translations-training#176
    quality +1
13. Improve translation of sentences containing numbers firefox-translations-training#173
    quality +1
14. Some words should be passing through untranslated (e.g. IPA characters, emojis, etc.) firefox-translations-training#171
    quality +1
15. Remove soft hyphen character firefox-translations-training#69
    quality +1
16. Investigate issues with sentencepiece sampling firefox-translations-training#411
    quality +1
    
17. Ensure numbers associated to units of measure are not translated as the same number with another unit of measure firefox-translations-training#577
    quality +1
18. Integrate other data augmentation types firefox-translations-training#255
    quality +1
19. Detect and prevent toxicity in models' output firefox-translations-training#167
    quality +1
20. Our models should be robust enough to translate a calendar firefox-translations-training#600
    quality +1
21. Retrain old models with robustness fixes #757
    quality +1
22. Make sure square brackets instead of parentheses don't lead to wrong translations firefox-translations-training#800
    quality +1
23. en-hr model does not always correctly distinguish between Indian and Native American firefox-translations-training#811
    feedback +1