List access tokens

curl -X GET "https://api.live.paisr.tech/v2/access-tokens" \
  -H "Authorization: Bearer <access_token>" \
  -H "User-Agent: MyApp/1.0" \
  -H "Content-Type: application/json"

{
  "success": true,
  "data": {
    "tokens": [
      {
        "id": "tkn_123456",
        "description": "Postman",
        "permissions": [
          {
            "id": "tpm_12345",
            "type": "invoices.read"
          }
        ],
        "created_at": "2024-01-15T10:30:00Z",
        "created_by": "tem_123456",
        "expires_at": "2024-01-15T10:30:00Z"
      }
    ]
  }
}