No database constraint that pfdcm service_name be unique

[Jennings Zhang]

It is possible to have duplicate entries:

xh :4010/pfdcm/                    
HTTP/1.1 200 OK
Content-Length: 170
Content-Type: application/json
Date: Tue, 04 Apr 2023 18:02:16 GMT
Server: uvicorn

{
    "data": [
        {
            "id": "642c65df734efb65f62dbccd",
            "service_name": "PFDCMLOCAL",
            "server_ip": "pfdcm",
            "server_port": "4005"
        }
    ],
    "code": 200,
    "message": "pfdcm data retrieved successfully"
}

[Sandip Samal]

Fixed-- DB constraint enforced for pfdcm service name to be unique.