Multivalued properties and "required" attribute lead to ill-functioning UI

In Studio Modeler, configure a document type Doc and add in its schema:

• a multivalued string which is required
• a multivalued complex (made of a string) which is required

In Studio Designer, configure the create screen (and edit, view, metadata screens) and witness that when adding the custom properties, Studio cannot render properly the UI (This is the issue in this ticket)

Deploy the project and boot and see that when creating a Doc document, then nothing tells the required properties are required (except dc:title) and hitting the document "create" button, the document is not created when the required properties are not filled in (this is expected excepted that no reason is given for the failure!) (See WEBUI-180)