Payload for family_upate and family_create differs from Akeneo API

[cplaetzinger]

The payload for events of type family_update and family_create differs from the JSON returned by the Akeneo HTTP API.

Steps to reproduce:

• Create a new family in the Akeneo web interface. Fill only the code attribute, leave other attributes empty
• The events API sends the following event

{
  "event_type": "family_created",
  "payload": {
    "code": "test_family_cp",
    "attributes": [
      "sku"
    ],
    "attribute_as_label": "sku",
    "attribute_as_image": null,
    "attribute_requirements": {
      "default": [
        "sku"
      ],
      "ecommerce": [
        "sku"
      ],
      "print": [
        "sku"
      ]
    },
    "labels": []
  }
}

• Getting the same family using the Akeneo HTTP API returns the following JSON:

{
  "code": "test_family_cp",
  "attributes": [
    "sku"
  ],
  "attribute_as_label": "sku",
  "attribute_as_image": null,
  "attribute_requirements": {
    "default": [
      "sku"
    ],
    "ecommerce": [
      "sku"
    ],
    "print": [
      "sku"
    ]
  },
  "labels": {}
}

As you can see there is a difference for the labels attribute. If the labels are empty the events API sends it as empty array but it should be an empty map/object.