fix(rights): Require English translation in rights fields

[Samk13]

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Description

This PR updates rights metadata validation to require an English
translation for title and description.
cleses: inveniosoftware/invenio-app-rdm#3394

AI was used to help generate many parts of this PR.

Could not reproduce it on latest...
still investigating it.

Checklist

Ticks in all boxes and 🟢 on all GitHub actions status checks are required to merge:

• I'm aware of the code of conduct.
• I've created logical separate commits and followed the commit message format.
• I've added relevant test cases.
• I've added relevant documentation.
• I've marked translation strings.
• I've identified the copyright holder(s) and updated copyright headers for touched files (>15 lines contributions).
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