View Designer: use selected-item(s) on top of value for suggestion widgets

In order to fix NXP-24471, the view desginer should generate

• multiple

      <nuxeo-directory-suggestion role="widget" label="[[i18n('label.dublincore.subjects')]]"
                                  directory-name="l10nsubjects"
                                  name="subjects"
                                  selected-items="{{document.properties.dc:subjects}}"
                                  multiple="true"
                                  dbl10n="true"
                                  placeholder="[[i18n('dublincoreEdit.directorySuggestion.placeholder')]]"
                                  min-chars="0">
      </nuxeo-directory-suggestion>
  

  or for single value

      <nuxeo-directory-suggestion role="widget" label="[[i18n('label.dublincore.coverage')]]"
                                  directory-name="l10ncoverage"
                                  name="coverage"
                                  selected-item="{{document.properties.dc:coverage}}"
                                  dbl10n="true"
                                  placeholder="[[i18n('dublincoreEdit.directorySuggestion.placeholder')]]"
                                  min-chars="0">
      </nuxeo-directory-suggestion>
  

  in document's layouts

This is also true for nuxeo-directory-suggestion, nuxeo-user-suggestion and nuxeo-document-suggestion.

TP >= 9.10-HF05

TODO

• For new d&d, generate code as described above
• For existing, when TP is 9.10 and old pattern is detected, add a validation warning:

  Since LTS 2017 HF05, code generation has changed for suggestion elements. Your code will keep working, but we recommend replacing these elements using drag and drop to benefit from the latest updates if you are using HF05 or newer.