Initial commit, basic proxying working

Myriad/Serialization/ShardInfoJsonConverter.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+using Myriad.Gateway;
+
+namespace Myriad.Serialization
+{
+    public class ShardInfoJsonConverter: JsonConverter<ShardInfo>
+    {
+        public override ShardInfo? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            var arr = JsonSerializer.Deserialize<int[]>(ref reader);
+            if (arr?.Length != 2)
+                throw new JsonException("Expected shard info as array of length 2");
+
+            return new ShardInfo(arr[0], arr[1]);
+        }
+
+        public override void Write(Utf8JsonWriter writer, ShardInfo value, JsonSerializerOptions options)
+        {
+            writer.WriteStartArray();
+            writer.WriteNumberValue(value.ShardId);
+            writer.WriteNumberValue(value.NumShards);
+            writer.WriteEndArray();
+        }
+    }
+}