Move resources and implementations for System.Text.Json for reuse across projects (#13626)

* Moved resources and implementations for System.Text.Json for reuse across projects.

* Move MvcBuilderExtensions as well

src/Umbraco.Infrastructure/Serialization/JsonObjectConverter.cs

@@ -0,0 +1,73 @@
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
+
+namespace Umbraco.Cms.Infrastructure.Serialization;
+
+public class JsonObjectConverter : JsonConverter<object>
+{
+    public override object Read(
+        ref Utf8JsonReader reader,
+        Type typeToConvert,
+        JsonSerializerOptions options) =>
+        ParseObject(ref reader);
+
+    public override void Write(
+        Utf8JsonWriter writer,
+        object objectToWrite,
+        JsonSerializerOptions options)
+    {
+        if (objectToWrite is null)
+        {
+            return;
+        }
+
+        // If an object is equals "new object()", Json.Serialize would recurse forever and cause a stack overflow
+        // We have no good way of checking if its an empty object
+        // which is why we try to check if the object has any properties, and thus will be empty.
+        if (objectToWrite.GetType().Name is "Object" && !objectToWrite.GetType().GetProperties().Any())
+        {
+            writer.WriteStartObject();
+            writer.WriteEndObject();
+        }
+        else
+        {
+            JsonSerializer.Serialize(writer, objectToWrite, objectToWrite.GetType(), options);
+        }
+    }
+
+    private object ParseObject(ref Utf8JsonReader reader)
+    {
+        if (reader.TokenType == JsonTokenType.StartArray)
+        {
+            var items = new List<object>();
+            while (reader.Read() && reader.TokenType != JsonTokenType.EndArray)
+            {
+                items.Add(ParseObject(ref reader));
+            }
+
+            return items.ToArray();
+        }
+
+        if (reader.TokenType == JsonTokenType.StartObject)
+        {
+            var jsonNode = JsonNode.Parse(ref reader);
+            if (jsonNode is JsonObject jsonObject)
+            {
+                return jsonObject;
+            }
+        }
+
+        return reader.TokenType switch
+        {
+            JsonTokenType.True => true,
+            JsonTokenType.False => false,
+            JsonTokenType.Number when reader.TryGetInt32(out int i) => i,
+            JsonTokenType.Number when reader.TryGetInt64(out long l) => l,
+            JsonTokenType.Number => reader.GetDouble(),
+            JsonTokenType.String when reader.TryGetDateTime(out DateTime datetime) => datetime,
+            JsonTokenType.String => reader.GetString()!,
+            _ => JsonDocument.ParseValue(ref reader).RootElement.Clone()
+        };
+    }
+}