[JsonSchemaExporter]: Respecting data annotations + schema version

Start at JsonSerializerOptions and the GetJsonSchemaAsNode entry point described in the issue, then trace the JsonSchemaExporter implementation. Review how data annotations and schema metadata are currently handled. Done means the requested annotation support and selectable draft version are defined and covered by the relevant exporter behavior.

Background and motivation

When trying to migrate from Newtonsoft.Json.Schema to pure JsonSchemaExporter (without any third party libraries) I have noticed that at least two features are missing.

1. Respecting data annotations (for example including in schema min and max of given type)
2. Possibility to select schema draft version

Would you guys consider adding them so the transition would be possible without taking dependency on external libraries?

Newtonsoft.Json.Schema:

{
  "$schema" : "http://json-schema.org/draft-07/schema#",
  "definitions" : {
    "Nested<UInt16>" : {
      "type" : "object",
      "properties" : {
        "required" : {
          "type" : "integer",
          "minimum" : 0.0,
          "maximum" : 65535.0
        },
        "nullable" : {
          "type" : [ "integer", "null" ],
          "minimum" : 0.0,
          "maximum" : 65535.0
        }
      },
      "required" : [ "required" ]
    }
  },
  "type" : "object",
  "properties" : {
    "required" : {
      "type" : "integer",
      "minimum" : 0.0,
      "maximum" : 65535.0
    },
    "nullable" : {
      "type" : [ "integer", "null" ],
      "minimum" : 0.0,
      "maximum" : 65535.0
    },
    "nested" : {
      "$ref" : "#/definitions/Nested<UInt16>"
    }
  },
  "required" : [ "required", "nested" ]
}

STJ:

{
  "type" : [ "object", "null" ],
  "properties" : {
    "required" : {
      "type" : "integer"
    },
    "nullable" : {
      "type" : [ "integer", "null" ]
    },
    "nested" : {
      "type" : "object",
      "properties" : {
        "required" : {
          "type" : "integer"
        },
        "nullable" : {
          "type" : [ "integer", "null" ]
        }
      },
      "required" : [ "required", "nullable" ]
    }
  },
  "required" : [ "required", "nullable", "nested" ]
}

API Proposal

JsonSerializerOptions options = new(JsonSerializerOptions.Default)
{
    RespectDataAnnotations= true,
    Version = "draft-07"
};

API Usage

JsonSerializerOptions options = new(JsonSerializerOptions.Default)
{
    PropertyNamingPolicy = JsonNamingPolicy.KebabCaseUpper,
    NumberHandling = JsonNumberHandling.WriteAsString,
    UnmappedMemberHandling = JsonUnmappedMemberHandling.Disallow,
    RespectDataAnnotations= true,
    Version = "draft-07"
};

JsonNode schema = options.GetJsonSchemaAsNode(typeof(MyPoco));
Console.WriteLine(schema.ToString());

Alternative Designs

No response

Risks

No response