[FC-0047] - Offline requirements for xblocks running

Drag and Drop

1. Click to the Drag and Drop item:
   
   Event: publish_event is sent.
   Request URL:
   http://local.overhang.io:8000/courses/course-v1:d+d+d/xblock/block-v1:d+d+d+type@drag-and-drop-v2+block@92cea1db16524b0baad9edb5f7e773dc/handler/publish_event
   Request Method: POST
   Payload: (Form Data)
   {"event_type":"edx.drag_and_drop_v2.item.picked_up","item_id":0}
   Response: {"result": "success"}
   

2. Click and move item to the Drag and Drop zone:
   
   1. Event: publish_event is sent.
   Request URL:
   http://local.overhang.io:8000/courses/course-v1:d+d+d/xblock/block-v1:d+d+d+type@drag-and-drop-v2+block@92cea1db16524b0baad9edb5f7e773dc/handler/publish_event
   Request Method: POST
   Payload: (Form Data)
   {"event_type":"edx.drag_and_drop_v2.item.picked_up","item_id":0}
   Response: {"result": "success"}
   
   2. Event: drop_item is sent.
   Request URL:
   http://local.overhang.io:8000/courses/course-v1:d+d+d/xblock/block-v1:d+d+d+type@drag-and-drop-v2+block@92cea1db16524b0baad9edb5f7e773dc/handler/drop_item
   Request Method: POST
   Payload: (Form Data)
   {"val":0,"zone":"top"}
   Response:

   {
       "correct": true,
       "grade": 0.4,
       "finished": false,
       "overall_feedback": [
           {
               "message": "Drag the items onto the image above.",
               "message_class": "initial"
           }
       ],
       "feedback": [
           {
               "message": "Correct! This one belongs to The Top Zone.",
               "message_class": null
           }
       ]
   }

   
   3. Event: publish_event is sent.

   Request URL:
   http://local.overhang.io:8000/courses/course-v1:d+d+d/xblock/block-v1:d+d+d+type@drag-and-drop-v2+block@92cea1db16524b0baad9edb5f7e773dc/handler/publish_event
   Request Method: POST
   Payload: (Form Data)
   {"event_type":"edx.drag_and_drop_v2.feedback.opened","content":"Correct! This one belongs to The Top Zone.","truncated":false}:
   Response: {"result": "success"}