[BUG] Deleting languages from the language list causes TranslationDictionary UI to act hairy

[japtar10101]

Describe the bug

Deleting languages from the language list causes TranslationDictionary UI to act hairy.

To Reproduce

Steps to reproduce the behavior:

1. Create at least 3 languages to support.
2. Create a TranslationDictionary.
3. Add one entry, with at least one of them have localization from the 2nd language.
4. Return back to the language list, and delete the 2nd language.
5. Open the TranslationDictionary again.

Expected behavior

The inspector will draw gracefully, with perhaps the old text either deleted or showing that the language it was for is no longer supported.

Actual behavior

I...actually don't remember, but it definitely doesn't do the above.

[japtar10101]

Fix #57 instead of this task.