Design.plone.contenttypes

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- Export children and parent UO in UO details.
[cekk]
- Export more infos in UO summary adapter.
[cekk]
- ufficio_responsabile in Servizio allows now 10 items.
[cekk]
- *ruolo* is now a Choice field and can be configured in control panel.
[cekk]

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- Add *ruolo* metadata for Persona and export it in summary serializer.
[cekk]

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- Fix addable content-types for Venue.
[cekk]

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- Import p.a.caching.
[cekk]

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- Fix typo.
[cekk]

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- p.a.caching rules for rest api services.
[cekk]