Add select widget for plone 7

[iFlameing]

[!CAUTION] The Volto Team has suspended its review of new pull requests from first-time contributors until the release of Plone 7, which is preliminarily scheduled for the second quarter of 2026. Read details.

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• [x] I signed and returned the Plone Contributor Agreement, and received and accepted an invitation to join a team in the Plone GitHub organization.
• [x] I verified there aren't other open pull requests for the same change.
• [x] I followed the guidelines in Contributing to Volto.
• [x] I succesfully ran code linting checks on my changes locally.
• [x] I succesfully ran unit tests on my changes locally.
• [x] I succesfully 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.

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[github-actions[bot]]

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Otherwise close this pull request. 🧹