You should add better error responses on Core CurrentsAPI

I sent the below request 

`curl --location --request GET 'https://api.currentsapi.services/v1/latest-news?language=hn&apiKey=VeryNiceKey'`

Notice I have sent language=hn and the API returned below resp - 
```
{
    "status": "500",
    "msg": "Server failed"
}
```

You should be more specific for the error. 