List client fields

{  "data": [    {      "created_at": "2024-01-01T00:00:00Z",      "description": null,      "id": "cf_a1b2c3d4e5f6",      "key": "company_name",      "label": "Company Name",      "object": "client_field",      "options": null,      "sensitive": false,      "sort_order": 1,      "type": "short_text",      "updated_at": "2024-01-01T00:00:00Z"    }  ]}