/1/Learner POST iframe hotfix

Fix: Restored array response format for POST /1/learner endpoint (regression from Nov 16) for iframe customers due to a inadvertent change to the Legacy APIs

Before :
  {
      "id": 287142,
      "code": "test123",
      "firstName": "John",
      "lastName": "Doe",
      ...
  }

After (fixed):
  [
      {
          "id": 287142,
          "code": "test123",
          "firstName": "John",
          "lastName": "Doe",
          ...
      }
	]