feat(#9683): add Arabic translations

[andrablaj]

Description

Add Arabic translations (see translation file).

Closes #9683

Code review checklist

• UI/UX backwards compatible: Test it works for the new design (enabled by default). And test it works in the old design, enable can_view_old_navigation permission to see the old design.
• Readable: Concise, well named, follows the style guide, documented if necessary.
• Documented: Configuration and user documentation on cht-docs
• Tested: Unit and/or e2e where appropriate
• Internationalised: All user facing text
• Backwards compatible: Works with existing data and configuration or includes a migration. Any breaking changes documented in the release notes.

Compose URLs

If Build CI hasn't passed, these may 404:

• Core
• CouchDB Single
• CouchDB Cluster

License

The software is provided under AGPL-3.0. Contributions to this project are accepted under the same license.

[andrablaj]

@m5r These are the Arabic translations shared by ICRC. I took a shot at creating the messages-ar.properties file starting from this Excel file. Would you mind looking at the video below and letting me know if the words are in the correct order when setting the browser to RTL? If yes, I can then mark the PR as ready for review. If not, I might need to start over with creating the properties file to ensure the words are correctly ordered. Thank you!

1.mp4

[m5r]

@andrablaj yes the words appear to be in correct order 👍

[m5r]

I can't help much with the translations specifically but on the implementation side, I believe you missed those files:
https://github.com/medic/cht-core/blob/9683-add-arabic/webapp/src/js/bootstrapper/translator.js
https://github.com/medic/cht-core/blob/9683-add-arabic/webapp/src/js/enketo/main.js

[andrablaj]

Thank you @m5r! I followed the steps in the guide and those files were not mentioned. I will dig into what other changes are needed and update the doc site accordingly. Let me get back here tomorrow or the day after tomorrow.

[andrablaj]

@m5r would you please look at the newer version of this PR?

For the webapp/src/js/bootstrapper/translator.js file, I used some translations from the messages-ar.properties file, and I used Google Translate for the longer sentences. We will have a dedicated QA activity with ICRC very soon with an Arabic-speaker and we can fix that file if something is not 100% accurate.