feat: Implement flag search

[inourbubble2]

Implemented GET /api/v1/flags and GET /api/v1/flags/{key}

Get Flags:

GET http://localhost:8080/api/v1/flags

HTTP/1.1 200 
Content-Type: application/json

{
  "status": "Success",
  "message": "Fetched all feature flags",
  "data": [
    {
      "key": "user-limit",
      "status": true,
      "type": "number",
      "defaultValue": {
        "number": "10"
      },
      "description": "description",
      "variants": [
        {
          "number": "10"
        },
        {
          "free": "100"
        }
      ],
      "createdBy": "username",
      "updatedBy": "username",
      "createdAt": "2025-02-17T00:27:06.122Z",
      "updatedAt": "2025-02-17T00:27:06.161Z"
    }
  ]
}

Get a flag by key:

GET http://localhost:8080/api/v1/flags/user-limit

HTTP/1.1 200 
Content-Type: application/json

{
  "status": "Success",
  "message": "Fetched a flag successfully",
  "data": {
    "key": "user-limit",
    "status": true,
    "type": "number",
    "defaultValue": {
      "number": "10"
    },
    "description": "description",
    "variants": [
      {
        "number": "10"
      },
      {
        "free": "100"
      }
    ],
    "createdBy": "username",
    "updatedBy": "username",
    "createdAt": "2025-02-17T00:27:06.122Z",
    "updatedAt": "2025-02-17T00:27:06.161Z"
  }
}

[Yg-Hong]

👍

[eunhwa99]

👍