Design.plone.contenttypes

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- Convert File into Modulo when trying to do a massive upload inside a Documento.
[cekk]
- Fix description for "a_cura_di_persone" field.
[cekk]
- Added "maximumSelectionSize" in RelatedItemsFieldWidget
[giulia]
- Add mostra_bottoni_condivisione field.
- Change block type: newsHome -> highlitedContent
[cekk]

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- Enabled "trasparenza" behavior. It's back!
[arsenico13]

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- Handle contents with old Richtext values in volto13 migration.
[cekk]

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- Volto 13 compatibility.
[cekk]

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- Add new behavior "design.plone.contenttypes.behavior.show_modified".
[cekk]

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- Removed field "Accedere al servizio" from Documento ct.
[daniele]