Invalid translation counts in the ExplorationOpportunityModel

[chris7716]

Steps to reproduce

1. Steps to reproduce(in dev server)
2. Submit translations for all cards of “Finding the value of a number” lesson
3. Accept all translation suggestions for that lesson
4. Change the second card of the lesson. Change the interaction to multiple choice and add three choices.
5. Add one correct interaction
6. Add two hints
7. Publish the lesson
8. Translate all the available cards for the lesson “Finding the value of a number” except one hint.
9. Accept all the submitted cards
10. Now go back to the lesson and revert the version back to the 2nd version of the lesson.
11. Now go back to the CD “Translate Text” tab.
12. You will see all the cards of the lesson again to translate.
13. Add translations to them
14. Now try to accept those translations
15. You will get the error for invalid translations count.

This might be happening since we do not create new version of EntityTranslationModel when we reverting an exploration.

This needs to be fixed because, if not, translators will occasionally run into this error and it will block all translation progress

Related: #20033

[masterboy376]

Hello @chris7716, is this reproducible in local serve.