Feature/ADF-1784/Side by side authoring

[jsconan]

Related to: https://oat-sa.atlassian.net/browse/ADF-1784

Summary

Add the side-by-side UI in the item authoring when translating.

Details

Add service connectors to:

• delete a translation
• update the progress

Note: the server side may need to be refactored as it is fast approach.

How to test

• checkout the branch: git checkout -t origin/feature/ADF-1784/side-by-side-authoring
• also make sure to checkout the companion PRs
• make sure to have the Feature Flags activated

FEATURE_FLAG_TRANSLATION_ENABLED=true
FEATURE_FLAG_UNIQUE_NUMERIC_QTI_IDENTIFIER=true
FEATURE_FLAG_TRANSLATION_DEVELOPER_MODE=true

• make sure to have the Item Translator role assigned to your user
• have an item ready for translation and add/edit a translation: it should present the side-by-side authoring
• from a regular item, also open the authoring: it should present the usual auhoring

[shaveko]

Tested locally, works well and looks good.

Nice job!

• 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