Move Files in metadata.json to root level

[micbar]

Description

Move Files to the instance level.

Motivation

1) Prepare for ACL

Model

{
  "date": "",
  "export_version": "exporter version",
  "instance": {
    "url": "https://oldinstance.com",
    "groups": [],
    "config": {
      "instanceId": "asdf",
      "salt": "asdfasdf",
      "secret": "asdg??"
    }
  },
  "users": [
    {
      "userId": "admin",
      "displayName": "admin",
      "settings": {},
      "shares": {}
    },
      "userId": "userXYId",
      "displayName": "userXY",
      "settings": {},
      "shares": {},
    }
  ],
  "files": [
    {
      "type": "folder",
      "path": "/folder1",
      "roles": [
        {
          "type": "owner",
          "users": [
            "user1"
          ],
          "groups": [
            "group1",
            "group2"
          ],
          "inherit": true
        }
      ]
    },
    {
      "type": "file",
      "path": "/folder1/file1.txt",
      "roles": [
        {
          "type": "editor",
          "users": [
            "user3"
          ],
          "groups": [
            "group2"
          ],
          "inherit": true
        },
        {
          "type": "viewer",
          "users": [
            "user4"
          ],
          "groups": [
            "group4",
            "group5"
          ],
          "inherit": true
        }
      ]
    }
  ]
}

[micbar]

@IljaN I had a start while changing the namespace.