Update conditionPayload properties

[RidhamShah]

Describe the bug
The ConditionPayload of experiment JSON on export/import contains full-object reference of Conditions and DecisionPoints. This needs to change to reference ID.

Old ConditionPayload API object return

{
      "createdAt": "2024-02-28T16:41:00.181Z",
      "updatedAt": "2024-02-28T16:41:00.181Z",
      "versionNumber": 1,
      "id": "dc72175a-55fb-40e6-98da-73a6de7744b4",
      "parentCondition": {
          "createdAt": "2024-02-28T16:41:00.181Z",
          "updatedAt": "2024-02-28T16:41:00.181Z",
          "versionNumber": 1,
          "id": "dd60067a-5258-4fde-bdd4-15860dbbf379",
          "twoCharacterId": "3U",
          "name": "",
          "description": null,
          "conditionCode": "question-hint-tutorbot",
          "assignmentWeight": 50,
          "order": 2
      },
      "decisionPoint": {
          "createdAt": "2024-02-28T16:41:00.181Z",
          "updatedAt": "2024-02-28T16:41:00.181Z",
          "versionNumber": 1,
          "id": "007ec826-93a2-40f3-822e-4c489c3280a9",
          "twoCharacterId": "V8",
          "site": "lesson-stream",
          "target": "question-hint",
          "description": "",
          "order": 1,
          "excludeIfReached": false
      },
      "payload": {
          "type": "string",
          "value": "custom-payload"
      }
}

New structure

{
    "createdAt": "2024-02-28T16:41:00.181Z",
    "updatedAt": "2024-02-28T16:41:00.181Z",
    "versionNumber": 1,
    "id": "dc72175a-55fb-40e6-98da-73a6de7744b4",
    "parentCondition": "dd60067a-5258-4fde-bdd4-15860dbbf379",
    "decisionPoint": "007ec826-93a2-40f3-822e-4c489c3280a9",
    "payload": {
        "type": "string",
        "value": "custom-payload"
    }
}