new languages from polyglot

[erral]

• I signed and returned the Plone Contributor Agreement, and received and accepted an invitation to join a team in the Plone GitHub organization.
• I verified there aren't other open pull requests for the same change.
• I followed the guidelines in Contributing to Volto.
• I successfully ran code linting checks on my changes locally.
• I successfully ran unit tests on my changes locally.
• I successfully ran acceptance tests on my changes locally.
• If needed, I added new tests for my changes.
• If needed, I added documentation for my changes, either in the Storybook or narrative documentation.
• I included a change log entry in my commits.

---

Translations for new languages coming from Polyglot project by @mpalomaki

[erral]

I created separated PRs for existing languages for eu, es and de.

Let's check what we have there, and we can discuss how to do the merging.

I would be in favor of opening one different PR for each language, but that could be hard to review and merge, but I think it is the way to go, as we would need to review those translations separatedly.