sync gateway 3.1 update role/user access changes for collections

When creating a user or role, there's a difference in 3.1 vs 3.0. A big concept is that channels are collection scoped rather than database scoped and defining admin_channels or all_channels needs to be with collection_access parameter if collections are defined.

The reason the non collection_access parameters exist is for backward compatibility on upgrade and that not all users of 3.1 are going to be using collections.

If collections are enabled:

{

  "collection_access": {

    "myscope": {

      "mycollection": {

        "admin_channels": [

          "string"

        ],

      },

  } 

If collections are not used (i.e. scopes is not defined on a database config.

{

        "admin_channels": [

          "string"

        ]

      },

}

}