Fix/ADF-1789/small issues

[jsconan]

Related to: https://oat-sa.atlassian.net/browse/ADF-1789

Summary

Fix for 2 small issues:

• when deleting a translation, the language needs to be available again in the dropdown
• the original resource language must not be available for translation

Details

Update the translation form component.

How to test

• check out the branch: git checkout -t origin/fix/ADF-1789/small-issues
• make sure to have the companion branch checked out and up to date too on the other extensions: feat/HKD-6/integration
• make sure to have the Feature Flags activated

FEATURE_FLAG_TRANSLATION_ENABLED=true
FEATURE_FLAG_UNIQUE_NUMERIC_QTI_IDENTIFIER=true

• make sure to have the Item Translator role assigned to your user
• have an item ready for translation
• add a translation and delete it: the language must be available again in the dropdown list
• the language of the main item must not be available for translation

[gabrielfs7]

Works good! Thanks, JS!

• New code is covered by tests (if applicable)
• Tests are running successfully (old and new ones) on my local machine (if applicable)
• New code is respecting code style rules
• New code is respecting best practices
• New code is not subject to concurrency issues (if applicable)
• Feature is working correctly on my local machine (if applicable)
• Acceptance criteria are respected
• Pull request title and description are meaningful

[shaveko]

Validated locally, issueas are fixed. Nice job!