Persona's item photo node should have mgnl:resource nodetype

Steps to reproduce

1. create new persona in Personas app
2. provide a photo and save
3. use JCR Browser (or JCR Tools/Dumper) to see a nodetype of photo node

Expected results

Node type of photo node should be mgnl:resource

Actual results

Node type of photo node is mgnl:contentNode

Development notes

add nodeType configuration to composite (wrapper) field itemProvider configuration

photo:
  $type: compositeField
  layout:
    class: info.magnolia.ui.framework.layout.SingleFieldLayoutProducer$Definition
  itemProvider:
    $type: jcrChildNodeProvider
    nodeType: mgnl:resource
  properties:
    image:
      class: info.magnolia.dam.app.field.DamUploadFieldDefinition
      allowedMimeTypePattern: image/*