Support application/problem+json

[tyzhnenko]

It would be great if BlackSheep supports application/problem+json in error responses

Example

POST /details HTTP/1.1
Host: account.example.com
Accept: application/json

{
  "age": 42.3,
  "profile": {
    "color": "yellow"
  }
}

HTTP/1.1 422 Unprocessable Content
Content-Type: application/problem+json
Content-Language: en

{
 "type": "https://example.net/validation-error",
 "title": "Your request is not valid.",
 "errors": [
             {
               "detail": "must be a positive integer",
               "pointer": "#/age"
             },
             {
               "detail": "must be 'green', 'red' or 'blue'",
               "pointer": "#/profile/color"
             }
          ]
}

Here's the RFC 9457