fix: handling serialized enum date in MongoDB effectively and more

[boscohyun]

• Resolve Handling a serialized enum type BsonValues in MongoDB effectively #454, Implement and register ProductSerializer #456
• See also Add Filtering and Sorting Features to Market GQL #402 (comment)

Examples

Case of product address 'ff6526b988ABDEEAA4D3Bf3e79cB681af4f929f5'

query {
  product(productId: "f0994e0c-0295-493d-a395-951ca7152954") {
    ... on ItemProduct {
       tradableItem {
        id
        itemType
        itemSubType
        elementalType
       }
    }
  }
}

{
  "data": {
    "product": {
      "tradableItem": {
        "id": 900109,
        "itemType": "CONSUMABLE",
        "itemSubType": "FOOD",
        "elementalType": "NORMAL"
      }
    }
  }
}

Case of product address '925A08670723Ab5B16F3Ca133bbf2D73DF4a1237'

query {
  product(productId: "adc9b9c8-ea71-4a56-9549-691f631a0b23") {
    ... on ItemProduct {
       tradableItem {
        id
        itemType
        itemSubType
        elementalType
       }
    }
  }
}

{
  "data": {
    "product": {
      "tradableItem": {
        "id": 10354002,
        "itemType": "EQUIPMENT",
        "itemSubType": "BELT",
        "elementalType": "WIND"
      }
    }
  }
}